[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"skill:01M6AFYA41TR7T9AP0F6PZEGCJ":3,"skill-same:01M6AFYA41TR7T9AP0F6PZEGCJ":143},{"skillNo":4,"name":5,"nameZh":6,"description":7,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":16,"categories":17,"keywords":31,"publishedAt":52,"linkOnly":53,"markdownContent":54,"markdownBody":55,"frontMatter":56,"refName":102,"commitSha":103,"skillDirectory":104,"forksCount":105,"repositoryHtmlUrl":106,"repositoryHomepageUrl":107,"ownerHtmlUrl":108,"ownerBlogUrl":109,"ownerDescription":110,"updatedAt":111,"install":112,"resources":125},"01M6AFYA41TR7T9AP0F6PZEGCJ","performing-oauth-scope-minimization-review",null,"Performs OAuth 2.0 scope minimization review to identify over-permissioned third-party application integrations, excessive API scopes, unused token grants, and risky OAuth consent patterns across identity providers and SaaS platforms. Activates for requests involving OAuth scope audit, API permission review, third-party app risk assessment, or consent grant minimization.","mukul975\u002FAnthropic-Cybersecurity-Skills","mukul975","https:\u002F\u002Favatars.githubusercontent.com\u002Fu\u002F42860185?v=4","01M6ADEQR8T5M4EEG6C67BQCWF","Mahipal","01M6ADJPMYWG1E5GM1FWBE3128",35990,"Apache-2.0","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fperforming-oauth-scope-minimization-review\u002FSKILL.md",[18,23,26],{"categoryNo":19,"categoryName":20,"taxonomyType":21,"taxonomyTypeDesc":22},"01JBSEEDCAT000000000000010","后端与接口","SCENARIO","使用场景",{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},"01JBSEEDCAT000000000000023","Skill与智能体开发",{"categoryNo":27,"categoryName":28,"taxonomyType":29,"taxonomyTypeDesc":30},"01JBSEEDCAT000000000000030","开发工程师","PROFESSION","适用职业",[32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51],"OAuth","performing oauth scope minimization review","review","t1078","security","api","third-party-risk","t1098","initial-access","saas","risk","Providers","identity","cybersecurity","api-security","audit","authentication","assessment","pr","risk assessment","2026-11-10 10:12:30",false,"---\nname: performing-oauth-scope-minimization-review\ndescription: 'Performs OAuth 2.0 scope minimization review to identify over-permissioned\n  third-party application integrations, excessive API scopes, unused token grants,\n  and risky OAuth consent patterns across identity providers and SaaS platforms. Activates\n  for requests involving OAuth scope audit, API permission review, third-party app\n  risk assessment, or consent grant minimization.\n\n  '\ndomain: cybersecurity\nsubdomain: identity-access-management\ntags:\n- OAuth\n- scope-minimization\n- API-security\n- consent-review\n- third-party-risk\n- token-audit\nversion: '1.0'\nauthor: mahipal\nlicense: Apache-2.0\nnist_csf:\n- PR.AA-01\n- PR.AA-02\n- PR.AA-05\n- PR.AA-06\nmitre_attack:\n- T1078\n- T1110\n- T1556\n- T1098\nmitre_f3:\n  version: '1.1'\n  tactics:\n  - initial-access\n  - positioning\n  - stealth\n  techniques:\n  - id: T1550.001\n    name: 'Use Alternate Authentication Material: Application Access Token'\n    tactic: initial-access\n    source: attack\n  - id: F1006.001\n    name: 'Account Takeover: Exposed API Key'\n    tactic: initial-access\n    source: f3\n  - id: F1004\n    name: Access with Stolen Session Cookie\n    tactic: initial-access\n    source: f3\n  - id: F1005.001\n    name: 'Account Manipulation: Account Linking'\n    tactic: positioning\n    source: f3\n  - id: T1539\n    name: Steal Web Session Cookie\n    tactic: positioning\n    source: attack\n  - id: F1023\n    name: Device Fingerprint Spoofing\n    tactic: stealth\n    source: f3\n---\n\n# Performing OAuth Scope Minimization Review\n\n## When to Use\n\n- Annual or quarterly review of third-party application OAuth permissions\n- After a security incident involving compromised OAuth tokens or unauthorized data access\n- Compliance audit requiring documentation of third-party data access (GDPR Article 28, SOC 2)\n- Discovery of shadow IT applications accessing organizational data via OAuth grants\n- Migration or consolidation of SaaS applications requiring permission cleanup\n- Implementing least-privilege principle for API integrations\n\n**Do not use** for reviewing first-party application permissions within the same trust boundary; OAuth scope minimization focuses on third-party and cross-boundary consent grants.\n\n## Prerequisites\n\n- Admin access to identity providers (Microsoft Entra ID, Okta, Google Workspace)\n- Microsoft Graph API permissions: Application.Read.All, OAuth2PermissionGrant.ReadWrite.All\n- Inventory of approved third-party integrations from procurement or IT governance\n- OAuth scope risk classification framework\n- Tools for token analysis (jwt.io for manual review, automated scripts for bulk analysis)\n\n## Workflow\n\n### Step 1: Inventory All OAuth Grants and Consent Permissions\n\nEnumerate all OAuth application registrations and delegated permissions:\n\n```python\n\"\"\"\nOAuth Grant Inventory - Microsoft Entra ID\nEnumerates all application registrations, service principals,\nand delegated\u002Fapplication permission grants.\n\"\"\"\nimport requests\nimport json\nfrom collections import defaultdict\n\nclass EntraOAuthAuditor:\n    def __init__(self, tenant_id, client_id, client_secret):\n        self.tenant_id = tenant_id\n        self.base_url = \"https:\u002F\u002Fgraph.microsoft.com\u002Fv1.0\"\n        self.token = self._get_token(client_id, client_secret)\n        self.headers = {\"Authorization\": f\"Bearer {self.token}\"}\n\n    def _get_token(self, client_id, client_secret):\n        url = f\"https:\u002F\u002Flogin.microsoftonline.com\u002F{self.tenant_id}\u002Foauth2\u002Fv2.0\u002Ftoken\"\n        response = requests.post(url, data={\n            \"grant_type\": \"client_credentials\",\n            \"client_id\": client_id,\n            \"client_secret\": client_secret,\n            \"scope\": \"https:\u002F\u002Fgraph.microsoft.com\u002F.default\"\n        })\n        return response.json()[\"access_token\"]\n\n    def get_all_service_principals(self):\n        \"\"\"Get all service principals (enterprise applications).\"\"\"\n        apps = []\n        url = f\"{self.base_url}\u002FservicePrincipals?$top=999&$select=id,appId,displayName,appOwnerOrganizationId,servicePrincipalType,accountEnabled,createdDateTime\"\n\n        while url:\n            response = requests.get(url, headers=self.headers)\n            data = response.json()\n            apps.extend(data.get(\"value\", []))\n            url = data.get(\"@odata.nextLink\")\n\n        return apps\n\n    def get_oauth2_permission_grants(self):\n        \"\"\"Get all delegated permission grants (user consent).\"\"\"\n        grants = []\n        url = f\"{self.base_url}\u002Foauth2PermissionGrants?$top=999\"\n\n        while url:\n            response = requests.get(url, headers=self.headers)\n            data = response.json()\n            grants.extend(data.get(\"value\", []))\n            url = data.get(\"@odata.nextLink\")\n\n        return grants\n\n    def get_app_role_assignments(self, sp_id):\n        \"\"\"Get application permission assignments for a service principal.\"\"\"\n        url = f\"{self.base_url}\u002FservicePrincipals\u002F{sp_id}\u002FappRoleAssignments\"\n        response = requests.get(url, headers=self.headers)\n        return response.json().get(\"value\", [])\n\n    def build_permission_inventory(self):\n        \"\"\"Build comprehensive OAuth permission inventory.\"\"\"\n        service_principals = self.get_all_service_principals()\n        delegated_grants = self.get_oauth2_permission_grants()\n\n        # Map service principal IDs to names\n        sp_map = {sp[\"id\"]: sp for sp in service_principals}\n\n        inventory = []\n\n        # Process delegated permissions\n        for grant in delegated_grants:\n            sp = sp_map.get(grant[\"clientId\"], {})\n            scopes = grant.get(\"scope\", \"\").split()\n\n            for scope in scopes:\n                if not scope:\n                    continue\n                inventory.append({\n                    \"app_name\": sp.get(\"displayName\", \"Unknown\"),\n                    \"app_id\": grant.get(\"clientId\"),\n                    \"publisher_tenant\": sp.get(\"appOwnerOrganizationId\"),\n                    \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != self.tenant_id,\n                    \"permission_type\": \"Delegated\",\n                    \"scope\": scope,\n                    \"consent_type\": grant.get(\"consentType\"),  # AllPrincipals or Principal\n                    \"principal_id\": grant.get(\"principalId\"),\n                    \"granted_date\": sp.get(\"createdDateTime\"),\n                    \"is_enabled\": sp.get(\"accountEnabled\", True)\n                })\n\n        # Process application permissions\n        for sp in service_principals:\n            app_roles = self.get_app_role_assignments(sp[\"id\"])\n            for role in app_roles:\n                inventory.append({\n                    \"app_name\": sp.get(\"displayName\"),\n                    \"app_id\": sp.get(\"id\"),\n                    \"publisher_tenant\": sp.get(\"appOwnerOrganizationId\"),\n                    \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != self.tenant_id,\n                    \"permission_type\": \"Application\",\n                    \"scope\": role.get(\"appRoleId\"),\n                    \"consent_type\": \"AdminConsent\",\n                    \"granted_date\": role.get(\"createdDateTime\"),\n                    \"is_enabled\": sp.get(\"accountEnabled\", True)\n                })\n\n        return inventory\n```\n\n### Step 2: Classify OAuth Scopes by Risk Level\n\nCategorize permissions based on data access sensitivity:\n\n```python\n\"\"\"\nOAuth Scope Risk Classification\nMaps API scopes to risk levels based on data sensitivity and access breadth.\n\"\"\"\n\nMICROSOFT_GRAPH_SCOPE_RISK = {\n    # CRITICAL - Full administrative or unrestricted access\n    \"critical\": {\n        \"scopes\": [\n            \"Directory.ReadWrite.All\",\n            \"RoleManagement.ReadWrite.Directory\",\n            \"Application.ReadWrite.All\",\n            \"AppRoleAssignment.ReadWrite.All\",\n            \"Mail.ReadWrite\",\n            \"Mail.Send\",\n            \"Files.ReadWrite.All\",\n            \"Sites.FullControl.All\",\n            \"User.ReadWrite.All\",\n            \"Group.ReadWrite.All\",\n            \"MailboxSettings.ReadWrite\",\n            \"full_access_as_app\",\n        ],\n        \"risk_description\": \"Can read\u002Fwrite all data, modify directory, or impersonate users\",\n        \"review_frequency\": \"Monthly\",\n        \"requires_admin_consent\": True\n    },\n    # HIGH - Broad read access or sensitive data write\n    \"high\": {\n        \"scopes\": [\n            \"Mail.Read\",\n            \"Mail.Read.Shared\",\n            \"Calendars.ReadWrite\",\n            \"Contacts.ReadWrite\",\n            \"Files.Read.All\",\n            \"Sites.Read.All\",\n            \"User.Read.All\",\n            \"Group.Read.All\",\n            \"Directory.Read.All\",\n            \"AuditLog.Read.All\",\n            \"SecurityEvents.ReadWrite.All\",\n            \"TeamSettings.ReadWrite.All\",\n        ],\n        \"risk_description\": \"Broad read access to sensitive organizational data\",\n        \"review_frequency\": \"Quarterly\",\n        \"requires_admin_consent\": True\n    },\n    # MEDIUM - Scoped data access\n    \"medium\": {\n        \"scopes\": [\n            \"Calendars.Read\",\n            \"Contacts.Read\",\n            \"Files.ReadWrite\",\n            \"Sites.ReadWrite.All\",\n            \"Tasks.ReadWrite\",\n            \"Notes.ReadWrite.All\",\n            \"Chat.ReadWrite\",\n            \"ChannelMessage.Send\",\n            \"Team.ReadBasic.All\",\n        ],\n        \"risk_description\": \"Scoped access to specific data types with write capability\",\n        \"review_frequency\": \"Semi-annually\"\n    },\n    # LOW - Minimal or user-profile only access\n    \"low\": {\n        \"scopes\": [\n            \"User.Read\",\n            \"openid\",\n            \"profile\",\n            \"email\",\n            \"offline_access\",\n            \"Calendars.Read.Shared\",\n            \"People.Read\",\n            \"User.ReadBasic.All\",\n        ],\n        \"risk_description\": \"Basic user profile or minimal scoped access\",\n        \"review_frequency\": \"Annually\"\n    }\n}\n\ndef classify_scope_risk(scope):\n    \"\"\"Classify a single OAuth scope by risk level.\"\"\"\n    for risk_level, config in MICROSOFT_GRAPH_SCOPE_RISK.items():\n        if scope in config[\"scopes\"]:\n            return {\n                \"scope\": scope,\n                \"risk_level\": risk_level,\n                \"description\": config[\"risk_description\"],\n                \"review_frequency\": config[\"review_frequency\"]\n            }\n    # Unknown scopes default to HIGH risk\n    return {\n        \"scope\": scope,\n        \"risk_level\": \"high\",\n        \"description\": \"Unknown scope - requires manual classification\",\n        \"review_frequency\": \"Quarterly\"\n    }\n\ndef analyze_app_risk(app_permissions):\n    \"\"\"Calculate aggregate risk score for an application's permissions.\"\"\"\n    risk_weights = {\"critical\": 40, \"high\": 20, \"medium\": 10, \"low\": 2}\n    total_score = 0\n    classified_scopes = []\n\n    for perm in app_permissions:\n        classification = classify_scope_risk(perm[\"scope\"])\n        classified_scopes.append(classification)\n        total_score += risk_weights.get(classification[\"risk_level\"], 10)\n\n    # Bonus risk for application (vs delegated) permissions\n    app_type_permissions = [p for p in app_permissions if p[\"permission_type\"] == \"Application\"]\n    total_score += len(app_type_permissions) * 15\n\n    # Bonus risk for admin-consented broad access\n    admin_consent = [p for p in app_permissions if p[\"consent_type\"] == \"AllPrincipals\"]\n    total_score += len(admin_consent) * 10\n\n    if total_score >= 100:\n        aggregate_risk = \"CRITICAL\"\n    elif total_score >= 60:\n        aggregate_risk = \"HIGH\"\n    elif total_score >= 30:\n        aggregate_risk = \"MEDIUM\"\n    else:\n        aggregate_risk = \"LOW\"\n\n    return {\n        \"total_score\": total_score,\n        \"aggregate_risk\": aggregate_risk,\n        \"scope_count\": len(app_permissions),\n        \"critical_scopes\": len([s for s in classified_scopes if s[\"risk_level\"] == \"critical\"]),\n        \"high_scopes\": len([s for s in classified_scopes if s[\"risk_level\"] == \"high\"]),\n        \"classified_scopes\": classified_scopes\n    }\n```\n\n### Step 3: Identify Over-Permissioned Applications\n\nDetect apps requesting more permissions than functionally needed:\n\n```python\n\"\"\"\nOver-Permission Detection\nIdentifies applications with excessive OAuth scopes relative to their function.\n\"\"\"\n\ndef detect_over_permissions(inventory, approved_apps_catalog):\n    \"\"\"\n    Compare actual permissions against approved scope catalog\n    to find over-permissioned applications.\n    \"\"\"\n    findings = []\n\n    # Group permissions by application\n    app_permissions = defaultdict(list)\n    for perm in inventory:\n        app_permissions[perm[\"app_name\"]].append(perm)\n\n    for app_name, permissions in app_permissions.items():\n        # Check against approved catalog\n        approved = approved_apps_catalog.get(app_name)\n\n        if not approved:\n            # Unknown\u002Funapproved application\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"UNAPPROVED_APPLICATION\",\n                \"severity\": \"HIGH\",\n                \"detail\": f\"Application not in approved catalog with {len(permissions)} permission grants\",\n                \"scopes\": [p[\"scope\"] for p in permissions],\n                \"recommendation\": \"Review and approve or revoke all permissions\"\n            })\n            continue\n\n        approved_scopes = set(approved.get(\"approved_scopes\", []))\n        actual_scopes = set(p[\"scope\"] for p in permissions)\n\n        # Find excessive scopes (granted but not approved)\n        excessive = actual_scopes - approved_scopes\n        if excessive:\n            risk = analyze_app_risk([p for p in permissions if p[\"scope\"] in excessive])\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"EXCESSIVE_SCOPES\",\n                \"severity\": risk[\"aggregate_risk\"],\n                \"detail\": f\"{len(excessive)} scopes beyond approved list\",\n                \"excessive_scopes\": list(excessive),\n                \"approved_scopes\": list(approved_scopes),\n                \"recommendation\": \"Remove excessive scopes or update approved catalog\"\n            })\n\n        # Find unused scopes (approved but activity logs show no API calls)\n        # This requires API activity log correlation\n        unused = approved_scopes - actual_scopes\n        if unused:\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"UNUSED_APPROVED_SCOPES\",\n                \"severity\": \"LOW\",\n                \"detail\": f\"{len(unused)} approved scopes not currently granted\",\n                \"unused_scopes\": list(unused)\n            })\n\n        # Check for overly broad permissions\n        broad_patterns = [\n            (\"Mail.ReadWrite\", \"Mail.Read\", \"Write access to mail when only read needed\"),\n            (\"Files.ReadWrite.All\", \"Files.Read.All\", \"Write access to all files when only read needed\"),\n            (\"Directory.ReadWrite.All\", \"Directory.Read.All\", \"Write access to directory when only read needed\"),\n            (\"User.ReadWrite.All\", \"User.Read.All\", \"Write access to users when only read needed\"),\n        ]\n\n        for broad, narrow, description in broad_patterns:\n            if broad in actual_scopes:\n                findings.append({\n                    \"app_name\": app_name,\n                    \"finding_type\": \"OVERLY_BROAD_SCOPE\",\n                    \"severity\": \"MEDIUM\",\n                    \"detail\": description,\n                    \"current_scope\": broad,\n                    \"recommended_scope\": narrow,\n                    \"recommendation\": f\"Downgrade from {broad} to {narrow}\"\n                })\n\n    return findings\n```\n\n### Step 4: Audit Token Usage and Detect Stale Grants\n\nIdentify OAuth tokens that are no longer actively used:\n\n```python\n\"\"\"\nToken Usage Audit\nAnalyzes sign-in logs and API activity to identify stale OAuth grants.\n\"\"\"\n\ndef audit_token_usage(auditor, days_inactive=90):\n    \"\"\"Identify OAuth grants with no recent API activity.\"\"\"\n    # Get sign-in activity for service principals\n    url = f\"{auditor.base_url}\u002FauditLogs\u002FsignIns\"\n    params = {\n        \"$filter\": f\"createdDateTime ge {(datetime.utcnow() - timedelta(days=days_inactive)).isoformat()}Z and signInEventTypes\u002Fany(t: t eq 'servicePrincipal')\",\n        \"$top\": 999\n    }\n\n    active_apps = set()\n    while url:\n        response = requests.get(url, headers=auditor.headers, params=params)\n        data = response.json()\n        for signin in data.get(\"value\", []):\n            active_apps.add(signin.get(\"appId\"))\n        url = data.get(\"@odata.nextLink\")\n        params = {}\n\n    # Compare against all granted apps\n    all_grants = auditor.get_oauth2_permission_grants()\n    sp_map = {sp[\"id\"]: sp for sp in auditor.get_all_service_principals()}\n\n    stale_grants = []\n    for grant in all_grants:\n        sp = sp_map.get(grant[\"clientId\"], {})\n        app_id = sp.get(\"appId\")\n\n        if app_id and app_id not in active_apps:\n            stale_grants.append({\n                \"app_name\": sp.get(\"displayName\", \"Unknown\"),\n                \"app_id\": app_id,\n                \"scopes\": grant.get(\"scope\", \"\").split(),\n                \"consent_type\": grant.get(\"consentType\"),\n                \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != auditor.tenant_id,\n                \"days_inactive\": days_inactive,\n                \"recommendation\": \"Revoke - no API activity in {days_inactive} days\"\n            })\n\n    return sorted(stale_grants, key=lambda x: len(x[\"scopes\"]), reverse=True)\n```\n\n### Step 5: Generate Remediation Plan and Execute Scope Reduction\n\nCreate and execute the scope minimization remediation plan:\n\n```python\n\"\"\"\nOAuth Scope Remediation\nGenerates and executes scope reduction actions.\n\"\"\"\n\ndef generate_remediation_plan(findings, stale_grants):\n    \"\"\"Create prioritized remediation plan.\"\"\"\n    plan = []\n\n    # Priority 1: Revoke unapproved applications\n    for f in findings:\n        if f[\"finding_type\"] == \"UNAPPROVED_APPLICATION\":\n            plan.append({\n                \"priority\": 1,\n                \"action\": \"REVOKE_ALL_PERMISSIONS\",\n                \"app_name\": f[\"app_name\"],\n                \"reason\": \"Unapproved third-party application\",\n                \"impact\": f\"Removes {len(f['scopes'])} permission grants\",\n                \"risk_if_not_addressed\": \"CRITICAL\"\n            })\n\n    # Priority 2: Remove excessive scopes from approved apps\n    for f in findings:\n        if f[\"finding_type\"] == \"EXCESSIVE_SCOPES\":\n            plan.append({\n                \"priority\": 2,\n                \"action\": \"REMOVE_EXCESSIVE_SCOPES\",\n                \"app_name\": f[\"app_name\"],\n                \"scopes_to_remove\": f[\"excessive_scopes\"],\n                \"reason\": \"Scopes beyond approved catalog\",\n                \"risk_if_not_addressed\": f[\"severity\"]\n            })\n\n    # Priority 3: Downgrade overly broad scopes\n    for f in findings:\n        if f[\"finding_type\"] == \"OVERLY_BROAD_SCOPE\":\n            plan.append({\n                \"priority\": 3,\n                \"action\": \"DOWNGRADE_SCOPE\",\n                \"app_name\": f[\"app_name\"],\n                \"current_scope\": f[\"current_scope\"],\n                \"target_scope\": f[\"recommended_scope\"],\n                \"reason\": f[\"detail\"],\n                \"risk_if_not_addressed\": \"MEDIUM\"\n            })\n\n    # Priority 4: Revoke stale grants\n    for grant in stale_grants:\n        plan.append({\n            \"priority\": 4,\n            \"action\": \"REVOKE_STALE_GRANT\",\n            \"app_name\": grant[\"app_name\"],\n            \"scopes_to_revoke\": grant[\"scopes\"],\n            \"reason\": f\"No API activity in {grant['days_inactive']} days\",\n            \"risk_if_not_addressed\": \"MEDIUM\"\n        })\n\n    return sorted(plan, key=lambda x: x[\"priority\"])\n\ndef execute_scope_reduction(auditor, grant_id, scopes_to_remove):\n    \"\"\"Remove specific scopes from an OAuth permission grant.\"\"\"\n    # Get current grant\n    url = f\"{auditor.base_url}\u002Foauth2PermissionGrants\u002F{grant_id}\"\n    response = requests.get(url, headers=auditor.headers)\n    current_grant = response.json()\n\n    current_scopes = set(current_grant.get(\"scope\", \"\").split())\n    updated_scopes = current_scopes - set(scopes_to_remove)\n\n    if not updated_scopes:\n        # Remove entire grant\n        requests.delete(url, headers=auditor.headers)\n        return {\"action\": \"grant_deleted\", \"grant_id\": grant_id}\n    else:\n        # Update with reduced scopes\n        update_body = {\"scope\": \" \".join(updated_scopes)}\n        requests.patch(url, headers=auditor.headers, json=update_body)\n        return {\n            \"action\": \"scopes_reduced\",\n            \"grant_id\": grant_id,\n            \"removed\": list(scopes_to_remove),\n            \"remaining\": list(updated_scopes)\n        }\n```\n\n## Key Concepts\n\n| Term | Definition |\n|------|------------|\n| **OAuth Scope** | Permission string defining the specific API access level granted to a client application (e.g., Mail.Read, Files.ReadWrite.All) |\n| **Delegated Permission** | OAuth scope exercised on behalf of a signed-in user, limited by both the app's permissions and the user's own access rights |\n| **Application Permission** | OAuth scope granted directly to the application without user context, providing access to all users' data (high risk) |\n| **Admin Consent** | Tenant-wide permission grant made by an administrator that applies to all users without individual consent |\n| **Scope Minimization** | Security principle of reducing OAuth permissions to the minimum set required for application functionality |\n| **Stale Grant** | OAuth permission that remains active but has no recent API usage, indicating the integration is abandoned or deprecated |\n\n## Tools & Systems\n\n- **Microsoft Entra Admin Center**: Portal for reviewing enterprise applications, consent permissions, and OAuth grant management\n- **Nudge Security**: SaaS security platform for discovering OAuth grants, assessing third-party risk, and automating scope reviews\n- **Cerby**: Non-SSO application management platform for auditing OAuth integrations and managing shared accounts\n- **Microsoft Graph API**: Programmatic interface for enumerating and modifying OAuth permission grants at scale\n\n## Common Scenarios\n\n### Scenario: Post-Breach OAuth Scope Audit\n\n**Context**: After a phishing attack compromised an admin account, investigation reveals the attacker registered a malicious OAuth application with Mail.ReadWrite and Files.ReadWrite.All scopes, exfiltrating 6 months of email. The organization needs a comprehensive OAuth scope review.\n\n**Approach**:\n1. Immediately revoke all OAuth grants from the compromised admin session\n2. Enumerate all service principals and permission grants across the tenant\n3. Flag all applications registered in the last 90 days for manual review\n4. Classify all third-party application scopes using the risk framework\n5. Identify applications with critical scopes (Mail.ReadWrite, Files.ReadWrite.All, Directory.ReadWrite.All)\n6. Cross-reference against approved application catalog from IT procurement\n7. Revoke all unapproved applications immediately\n8. Downgrade over-permissioned approved applications to minimum required scopes\n9. Implement admin consent workflow to prevent future uncontrolled OAuth grants\n10. Enable consent policy requiring admin approval for high-risk scopes\n\n**Pitfalls**:\n- Revoking permissions for business-critical integrations without coordination causes service disruption\n- Not checking for application-level permissions (vs delegated) which are higher risk and often overlooked\n- Missing multi-tenant applications where the publisher tenant differs from the consuming tenant\n- Not implementing ongoing monitoring to detect new unauthorized OAuth grants after remediation\n\n## Output Format\n\n```\nOAUTH SCOPE MINIMIZATION REVIEW REPORT\n=========================================\nTenant:              corp.onmicrosoft.com\nReview Period:       2026-02-01 to 2026-02-24\nTotal Applications:  147\nThird-Party Apps:    98\nFirst-Party Apps:    49\n\nPERMISSION INVENTORY\nTotal OAuth Grants:          487\n  Delegated Permissions:     312\n  Application Permissions:   175\n  Admin-Consented:           89\n  User-Consented:            223\n\nRISK CLASSIFICATION\nCritical Risk Apps:     7\n  - UnknownCRMApp (Mail.ReadWrite, Files.ReadWrite.All - UNAPPROVED)\n  - LegacySync (Directory.ReadWrite.All - EXCESSIVE)\n  - DevToolX (Application.ReadWrite.All - OVERLY BROAD)\nHigh Risk Apps:         18\nMedium Risk Apps:       34\nLow Risk Apps:          88\n\nFINDINGS\nUnapproved Applications:        12 (REVOKE IMMEDIATELY)\nExcessive Scopes:               23 apps with scopes beyond approved list\nOverly Broad Permissions:       15 apps that can be downgraded\nStale Grants (90+ days):        31 apps with no recent API activity\n\nREMEDIATION PLAN\nPriority 1 (Immediate):    12 unapproved app revocations\nPriority 2 (This Week):    23 excessive scope removals\nPriority 3 (This Month):   15 scope downgrades\nPriority 4 (Next Quarter): 31 stale grant revocations\n\nEstimated Scope Reduction:  34% of total permissions\n```\n","# Performing OAuth Scope Minimization Review\n\n## When to Use\n\n- Annual or quarterly review of third-party application OAuth permissions\n- After a security incident involving compromised OAuth tokens or unauthorized data access\n- Compliance audit requiring documentation of third-party data access (GDPR Article 28, SOC 2)\n- Discovery of shadow IT applications accessing organizational data via OAuth grants\n- Migration or consolidation of SaaS applications requiring permission cleanup\n- Implementing least-privilege principle for API integrations\n\n**Do not use** for reviewing first-party application permissions within the same trust boundary; OAuth scope minimization focuses on third-party and cross-boundary consent grants.\n\n## Prerequisites\n\n- Admin access to identity providers (Microsoft Entra ID, Okta, Google Workspace)\n- Microsoft Graph API permissions: Application.Read.All, OAuth2PermissionGrant.ReadWrite.All\n- Inventory of approved third-party integrations from procurement or IT governance\n- OAuth scope risk classification framework\n- Tools for token analysis (jwt.io for manual review, automated scripts for bulk analysis)\n\n## Workflow\n\n### Step 1: Inventory All OAuth Grants and Consent Permissions\n\nEnumerate all OAuth application registrations and delegated permissions:\n\n```python\n\"\"\"\nOAuth Grant Inventory - Microsoft Entra ID\nEnumerates all application registrations, service principals,\nand delegated\u002Fapplication permission grants.\n\"\"\"\nimport requests\nimport json\nfrom collections import defaultdict\n\nclass EntraOAuthAuditor:\n    def __init__(self, tenant_id, client_id, client_secret):\n        self.tenant_id = tenant_id\n        self.base_url = \"https:\u002F\u002Fgraph.microsoft.com\u002Fv1.0\"\n        self.token = self._get_token(client_id, client_secret)\n        self.headers = {\"Authorization\": f\"Bearer {self.token}\"}\n\n    def _get_token(self, client_id, client_secret):\n        url = f\"https:\u002F\u002Flogin.microsoftonline.com\u002F{self.tenant_id}\u002Foauth2\u002Fv2.0\u002Ftoken\"\n        response = requests.post(url, data={\n            \"grant_type\": \"client_credentials\",\n            \"client_id\": client_id,\n            \"client_secret\": client_secret,\n            \"scope\": \"https:\u002F\u002Fgraph.microsoft.com\u002F.default\"\n        })\n        return response.json()[\"access_token\"]\n\n    def get_all_service_principals(self):\n        \"\"\"Get all service principals (enterprise applications).\"\"\"\n        apps = []\n        url = f\"{self.base_url}\u002FservicePrincipals?$top=999&$select=id,appId,displayName,appOwnerOrganizationId,servicePrincipalType,accountEnabled,createdDateTime\"\n\n        while url:\n            response = requests.get(url, headers=self.headers)\n            data = response.json()\n            apps.extend(data.get(\"value\", []))\n            url = data.get(\"@odata.nextLink\")\n\n        return apps\n\n    def get_oauth2_permission_grants(self):\n        \"\"\"Get all delegated permission grants (user consent).\"\"\"\n        grants = []\n        url = f\"{self.base_url}\u002Foauth2PermissionGrants?$top=999\"\n\n        while url:\n            response = requests.get(url, headers=self.headers)\n            data = response.json()\n            grants.extend(data.get(\"value\", []))\n            url = data.get(\"@odata.nextLink\")\n\n        return grants\n\n    def get_app_role_assignments(self, sp_id):\n        \"\"\"Get application permission assignments for a service principal.\"\"\"\n        url = f\"{self.base_url}\u002FservicePrincipals\u002F{sp_id}\u002FappRoleAssignments\"\n        response = requests.get(url, headers=self.headers)\n        return response.json().get(\"value\", [])\n\n    def build_permission_inventory(self):\n        \"\"\"Build comprehensive OAuth permission inventory.\"\"\"\n        service_principals = self.get_all_service_principals()\n        delegated_grants = self.get_oauth2_permission_grants()\n\n        # Map service principal IDs to names\n        sp_map = {sp[\"id\"]: sp for sp in service_principals}\n\n        inventory = []\n\n        # Process delegated permissions\n        for grant in delegated_grants:\n            sp = sp_map.get(grant[\"clientId\"], {})\n            scopes = grant.get(\"scope\", \"\").split()\n\n            for scope in scopes:\n                if not scope:\n                    continue\n                inventory.append({\n                    \"app_name\": sp.get(\"displayName\", \"Unknown\"),\n                    \"app_id\": grant.get(\"clientId\"),\n                    \"publisher_tenant\": sp.get(\"appOwnerOrganizationId\"),\n                    \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != self.tenant_id,\n                    \"permission_type\": \"Delegated\",\n                    \"scope\": scope,\n                    \"consent_type\": grant.get(\"consentType\"),  # AllPrincipals or Principal\n                    \"principal_id\": grant.get(\"principalId\"),\n                    \"granted_date\": sp.get(\"createdDateTime\"),\n                    \"is_enabled\": sp.get(\"accountEnabled\", True)\n                })\n\n        # Process application permissions\n        for sp in service_principals:\n            app_roles = self.get_app_role_assignments(sp[\"id\"])\n            for role in app_roles:\n                inventory.append({\n                    \"app_name\": sp.get(\"displayName\"),\n                    \"app_id\": sp.get(\"id\"),\n                    \"publisher_tenant\": sp.get(\"appOwnerOrganizationId\"),\n                    \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != self.tenant_id,\n                    \"permission_type\": \"Application\",\n                    \"scope\": role.get(\"appRoleId\"),\n                    \"consent_type\": \"AdminConsent\",\n                    \"granted_date\": role.get(\"createdDateTime\"),\n                    \"is_enabled\": sp.get(\"accountEnabled\", True)\n                })\n\n        return inventory\n```\n\n### Step 2: Classify OAuth Scopes by Risk Level\n\nCategorize permissions based on data access sensitivity:\n\n```python\n\"\"\"\nOAuth Scope Risk Classification\nMaps API scopes to risk levels based on data sensitivity and access breadth.\n\"\"\"\n\nMICROSOFT_GRAPH_SCOPE_RISK = {\n    # CRITICAL - Full administrative or unrestricted access\n    \"critical\": {\n        \"scopes\": [\n            \"Directory.ReadWrite.All\",\n            \"RoleManagement.ReadWrite.Directory\",\n            \"Application.ReadWrite.All\",\n            \"AppRoleAssignment.ReadWrite.All\",\n            \"Mail.ReadWrite\",\n            \"Mail.Send\",\n            \"Files.ReadWrite.All\",\n            \"Sites.FullControl.All\",\n            \"User.ReadWrite.All\",\n            \"Group.ReadWrite.All\",\n            \"MailboxSettings.ReadWrite\",\n            \"full_access_as_app\",\n        ],\n        \"risk_description\": \"Can read\u002Fwrite all data, modify directory, or impersonate users\",\n        \"review_frequency\": \"Monthly\",\n        \"requires_admin_consent\": True\n    },\n    # HIGH - Broad read access or sensitive data write\n    \"high\": {\n        \"scopes\": [\n            \"Mail.Read\",\n            \"Mail.Read.Shared\",\n            \"Calendars.ReadWrite\",\n            \"Contacts.ReadWrite\",\n            \"Files.Read.All\",\n            \"Sites.Read.All\",\n            \"User.Read.All\",\n            \"Group.Read.All\",\n            \"Directory.Read.All\",\n            \"AuditLog.Read.All\",\n            \"SecurityEvents.ReadWrite.All\",\n            \"TeamSettings.ReadWrite.All\",\n        ],\n        \"risk_description\": \"Broad read access to sensitive organizational data\",\n        \"review_frequency\": \"Quarterly\",\n        \"requires_admin_consent\": True\n    },\n    # MEDIUM - Scoped data access\n    \"medium\": {\n        \"scopes\": [\n            \"Calendars.Read\",\n            \"Contacts.Read\",\n            \"Files.ReadWrite\",\n            \"Sites.ReadWrite.All\",\n            \"Tasks.ReadWrite\",\n            \"Notes.ReadWrite.All\",\n            \"Chat.ReadWrite\",\n            \"ChannelMessage.Send\",\n            \"Team.ReadBasic.All\",\n        ],\n        \"risk_description\": \"Scoped access to specific data types with write capability\",\n        \"review_frequency\": \"Semi-annually\"\n    },\n    # LOW - Minimal or user-profile only access\n    \"low\": {\n        \"scopes\": [\n            \"User.Read\",\n            \"openid\",\n            \"profile\",\n            \"email\",\n            \"offline_access\",\n            \"Calendars.Read.Shared\",\n            \"People.Read\",\n            \"User.ReadBasic.All\",\n        ],\n        \"risk_description\": \"Basic user profile or minimal scoped access\",\n        \"review_frequency\": \"Annually\"\n    }\n}\n\ndef classify_scope_risk(scope):\n    \"\"\"Classify a single OAuth scope by risk level.\"\"\"\n    for risk_level, config in MICROSOFT_GRAPH_SCOPE_RISK.items():\n        if scope in config[\"scopes\"]:\n            return {\n                \"scope\": scope,\n                \"risk_level\": risk_level,\n                \"description\": config[\"risk_description\"],\n                \"review_frequency\": config[\"review_frequency\"]\n            }\n    # Unknown scopes default to HIGH risk\n    return {\n        \"scope\": scope,\n        \"risk_level\": \"high\",\n        \"description\": \"Unknown scope - requires manual classification\",\n        \"review_frequency\": \"Quarterly\"\n    }\n\ndef analyze_app_risk(app_permissions):\n    \"\"\"Calculate aggregate risk score for an application's permissions.\"\"\"\n    risk_weights = {\"critical\": 40, \"high\": 20, \"medium\": 10, \"low\": 2}\n    total_score = 0\n    classified_scopes = []\n\n    for perm in app_permissions:\n        classification = classify_scope_risk(perm[\"scope\"])\n        classified_scopes.append(classification)\n        total_score += risk_weights.get(classification[\"risk_level\"], 10)\n\n    # Bonus risk for application (vs delegated) permissions\n    app_type_permissions = [p for p in app_permissions if p[\"permission_type\"] == \"Application\"]\n    total_score += len(app_type_permissions) * 15\n\n    # Bonus risk for admin-consented broad access\n    admin_consent = [p for p in app_permissions if p[\"consent_type\"] == \"AllPrincipals\"]\n    total_score += len(admin_consent) * 10\n\n    if total_score >= 100:\n        aggregate_risk = \"CRITICAL\"\n    elif total_score >= 60:\n        aggregate_risk = \"HIGH\"\n    elif total_score >= 30:\n        aggregate_risk = \"MEDIUM\"\n    else:\n        aggregate_risk = \"LOW\"\n\n    return {\n        \"total_score\": total_score,\n        \"aggregate_risk\": aggregate_risk,\n        \"scope_count\": len(app_permissions),\n        \"critical_scopes\": len([s for s in classified_scopes if s[\"risk_level\"] == \"critical\"]),\n        \"high_scopes\": len([s for s in classified_scopes if s[\"risk_level\"] == \"high\"]),\n        \"classified_scopes\": classified_scopes\n    }\n```\n\n### Step 3: Identify Over-Permissioned Applications\n\nDetect apps requesting more permissions than functionally needed:\n\n```python\n\"\"\"\nOver-Permission Detection\nIdentifies applications with excessive OAuth scopes relative to their function.\n\"\"\"\n\ndef detect_over_permissions(inventory, approved_apps_catalog):\n    \"\"\"\n    Compare actual permissions against approved scope catalog\n    to find over-permissioned applications.\n    \"\"\"\n    findings = []\n\n    # Group permissions by application\n    app_permissions = defaultdict(list)\n    for perm in inventory:\n        app_permissions[perm[\"app_name\"]].append(perm)\n\n    for app_name, permissions in app_permissions.items():\n        # Check against approved catalog\n        approved = approved_apps_catalog.get(app_name)\n\n        if not approved:\n            # Unknown\u002Funapproved application\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"UNAPPROVED_APPLICATION\",\n                \"severity\": \"HIGH\",\n                \"detail\": f\"Application not in approved catalog with {len(permissions)} permission grants\",\n                \"scopes\": [p[\"scope\"] for p in permissions],\n                \"recommendation\": \"Review and approve or revoke all permissions\"\n            })\n            continue\n\n        approved_scopes = set(approved.get(\"approved_scopes\", []))\n        actual_scopes = set(p[\"scope\"] for p in permissions)\n\n        # Find excessive scopes (granted but not approved)\n        excessive = actual_scopes - approved_scopes\n        if excessive:\n            risk = analyze_app_risk([p for p in permissions if p[\"scope\"] in excessive])\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"EXCESSIVE_SCOPES\",\n                \"severity\": risk[\"aggregate_risk\"],\n                \"detail\": f\"{len(excessive)} scopes beyond approved list\",\n                \"excessive_scopes\": list(excessive),\n                \"approved_scopes\": list(approved_scopes),\n                \"recommendation\": \"Remove excessive scopes or update approved catalog\"\n            })\n\n        # Find unused scopes (approved but activity logs show no API calls)\n        # This requires API activity log correlation\n        unused = approved_scopes - actual_scopes\n        if unused:\n            findings.append({\n                \"app_name\": app_name,\n                \"finding_type\": \"UNUSED_APPROVED_SCOPES\",\n                \"severity\": \"LOW\",\n                \"detail\": f\"{len(unused)} approved scopes not currently granted\",\n                \"unused_scopes\": list(unused)\n            })\n\n        # Check for overly broad permissions\n        broad_patterns = [\n            (\"Mail.ReadWrite\", \"Mail.Read\", \"Write access to mail when only read needed\"),\n            (\"Files.ReadWrite.All\", \"Files.Read.All\", \"Write access to all files when only read needed\"),\n            (\"Directory.ReadWrite.All\", \"Directory.Read.All\", \"Write access to directory when only read needed\"),\n            (\"User.ReadWrite.All\", \"User.Read.All\", \"Write access to users when only read needed\"),\n        ]\n\n        for broad, narrow, description in broad_patterns:\n            if broad in actual_scopes:\n                findings.append({\n                    \"app_name\": app_name,\n                    \"finding_type\": \"OVERLY_BROAD_SCOPE\",\n                    \"severity\": \"MEDIUM\",\n                    \"detail\": description,\n                    \"current_scope\": broad,\n                    \"recommended_scope\": narrow,\n                    \"recommendation\": f\"Downgrade from {broad} to {narrow}\"\n                })\n\n    return findings\n```\n\n### Step 4: Audit Token Usage and Detect Stale Grants\n\nIdentify OAuth tokens that are no longer actively used:\n\n```python\n\"\"\"\nToken Usage Audit\nAnalyzes sign-in logs and API activity to identify stale OAuth grants.\n\"\"\"\n\ndef audit_token_usage(auditor, days_inactive=90):\n    \"\"\"Identify OAuth grants with no recent API activity.\"\"\"\n    # Get sign-in activity for service principals\n    url = f\"{auditor.base_url}\u002FauditLogs\u002FsignIns\"\n    params = {\n        \"$filter\": f\"createdDateTime ge {(datetime.utcnow() - timedelta(days=days_inactive)).isoformat()}Z and signInEventTypes\u002Fany(t: t eq 'servicePrincipal')\",\n        \"$top\": 999\n    }\n\n    active_apps = set()\n    while url:\n        response = requests.get(url, headers=auditor.headers, params=params)\n        data = response.json()\n        for signin in data.get(\"value\", []):\n            active_apps.add(signin.get(\"appId\"))\n        url = data.get(\"@odata.nextLink\")\n        params = {}\n\n    # Compare against all granted apps\n    all_grants = auditor.get_oauth2_permission_grants()\n    sp_map = {sp[\"id\"]: sp for sp in auditor.get_all_service_principals()}\n\n    stale_grants = []\n    for grant in all_grants:\n        sp = sp_map.get(grant[\"clientId\"], {})\n        app_id = sp.get(\"appId\")\n\n        if app_id and app_id not in active_apps:\n            stale_grants.append({\n                \"app_name\": sp.get(\"displayName\", \"Unknown\"),\n                \"app_id\": app_id,\n                \"scopes\": grant.get(\"scope\", \"\").split(),\n                \"consent_type\": grant.get(\"consentType\"),\n                \"is_third_party\": sp.get(\"appOwnerOrganizationId\") != auditor.tenant_id,\n                \"days_inactive\": days_inactive,\n                \"recommendation\": \"Revoke - no API activity in {days_inactive} days\"\n            })\n\n    return sorted(stale_grants, key=lambda x: len(x[\"scopes\"]), reverse=True)\n```\n\n### Step 5: Generate Remediation Plan and Execute Scope Reduction\n\nCreate and execute the scope minimization remediation plan:\n\n```python\n\"\"\"\nOAuth Scope Remediation\nGenerates and executes scope reduction actions.\n\"\"\"\n\ndef generate_remediation_plan(findings, stale_grants):\n    \"\"\"Create prioritized remediation plan.\"\"\"\n    plan = []\n\n    # Priority 1: Revoke unapproved applications\n    for f in findings:\n        if f[\"finding_type\"] == \"UNAPPROVED_APPLICATION\":\n            plan.append({\n                \"priority\": 1,\n                \"action\": \"REVOKE_ALL_PERMISSIONS\",\n                \"app_name\": f[\"app_name\"],\n                \"reason\": \"Unapproved third-party application\",\n                \"impact\": f\"Removes {len(f['scopes'])} permission grants\",\n                \"risk_if_not_addressed\": \"CRITICAL\"\n            })\n\n    # Priority 2: Remove excessive scopes from approved apps\n    for f in findings:\n        if f[\"finding_type\"] == \"EXCESSIVE_SCOPES\":\n            plan.append({\n                \"priority\": 2,\n                \"action\": \"REMOVE_EXCESSIVE_SCOPES\",\n                \"app_name\": f[\"app_name\"],\n                \"scopes_to_remove\": f[\"excessive_scopes\"],\n                \"reason\": \"Scopes beyond approved catalog\",\n                \"risk_if_not_addressed\": f[\"severity\"]\n            })\n\n    # Priority 3: Downgrade overly broad scopes\n    for f in findings:\n        if f[\"finding_type\"] == \"OVERLY_BROAD_SCOPE\":\n            plan.append({\n                \"priority\": 3,\n                \"action\": \"DOWNGRADE_SCOPE\",\n                \"app_name\": f[\"app_name\"],\n                \"current_scope\": f[\"current_scope\"],\n                \"target_scope\": f[\"recommended_scope\"],\n                \"reason\": f[\"detail\"],\n                \"risk_if_not_addressed\": \"MEDIUM\"\n            })\n\n    # Priority 4: Revoke stale grants\n    for grant in stale_grants:\n        plan.append({\n            \"priority\": 4,\n            \"action\": \"REVOKE_STALE_GRANT\",\n            \"app_name\": grant[\"app_name\"],\n            \"scopes_to_revoke\": grant[\"scopes\"],\n            \"reason\": f\"No API activity in {grant['days_inactive']} days\",\n            \"risk_if_not_addressed\": \"MEDIUM\"\n        })\n\n    return sorted(plan, key=lambda x: x[\"priority\"])\n\ndef execute_scope_reduction(auditor, grant_id, scopes_to_remove):\n    \"\"\"Remove specific scopes from an OAuth permission grant.\"\"\"\n    # Get current grant\n    url = f\"{auditor.base_url}\u002Foauth2PermissionGrants\u002F{grant_id}\"\n    response = requests.get(url, headers=auditor.headers)\n    current_grant = response.json()\n\n    current_scopes = set(current_grant.get(\"scope\", \"\").split())\n    updated_scopes = current_scopes - set(scopes_to_remove)\n\n    if not updated_scopes:\n        # Remove entire grant\n        requests.delete(url, headers=auditor.headers)\n        return {\"action\": \"grant_deleted\", \"grant_id\": grant_id}\n    else:\n        # Update with reduced scopes\n        update_body = {\"scope\": \" \".join(updated_scopes)}\n        requests.patch(url, headers=auditor.headers, json=update_body)\n        return {\n            \"action\": \"scopes_reduced\",\n            \"grant_id\": grant_id,\n            \"removed\": list(scopes_to_remove),\n            \"remaining\": list(updated_scopes)\n        }\n```\n\n## Key Concepts\n\n| Term | Definition |\n|------|------------|\n| **OAuth Scope** | Permission string defining the specific API access level granted to a client application (e.g., Mail.Read, Files.ReadWrite.All) |\n| **Delegated Permission** | OAuth scope exercised on behalf of a signed-in user, limited by both the app's permissions and the user's own access rights |\n| **Application Permission** | OAuth scope granted directly to the application without user context, providing access to all users' data (high risk) |\n| **Admin Consent** | Tenant-wide permission grant made by an administrator that applies to all users without individual consent |\n| **Scope Minimization** | Security principle of reducing OAuth permissions to the minimum set required for application functionality |\n| **Stale Grant** | OAuth permission that remains active but has no recent API usage, indicating the integration is abandoned or deprecated |\n\n## Tools & Systems\n\n- **Microsoft Entra Admin Center**: Portal for reviewing enterprise applications, consent permissions, and OAuth grant management\n- **Nudge Security**: SaaS security platform for discovering OAuth grants, assessing third-party risk, and automating scope reviews\n- **Cerby**: Non-SSO application management platform for auditing OAuth integrations and managing shared accounts\n- **Microsoft Graph API**: Programmatic interface for enumerating and modifying OAuth permission grants at scale\n\n## Common Scenarios\n\n### Scenario: Post-Breach OAuth Scope Audit\n\n**Context**: After a phishing attack compromised an admin account, investigation reveals the attacker registered a malicious OAuth application with Mail.ReadWrite and Files.ReadWrite.All scopes, exfiltrating 6 months of email. The organization needs a comprehensive OAuth scope review.\n\n**Approach**:\n1. Immediately revoke all OAuth grants from the compromised admin session\n2. Enumerate all service principals and permission grants across the tenant\n3. Flag all applications registered in the last 90 days for manual review\n4. Classify all third-party application scopes using the risk framework\n5. Identify applications with critical scopes (Mail.ReadWrite, Files.ReadWrite.All, Directory.ReadWrite.All)\n6. Cross-reference against approved application catalog from IT procurement\n7. Revoke all unapproved applications immediately\n8. Downgrade over-permissioned approved applications to minimum required scopes\n9. Implement admin consent workflow to prevent future uncontrolled OAuth grants\n10. Enable consent policy requiring admin approval for high-risk scopes\n\n**Pitfalls**:\n- Revoking permissions for business-critical integrations without coordination causes service disruption\n- Not checking for application-level permissions (vs delegated) which are higher risk and often overlooked\n- Missing multi-tenant applications where the publisher tenant differs from the consuming tenant\n- Not implementing ongoing monitoring to detect new unauthorized OAuth grants after remediation\n\n## Output Format\n\n```\nOAUTH SCOPE MINIMIZATION REVIEW REPORT\n=========================================\nTenant:              corp.onmicrosoft.com\nReview Period:       2026-02-01 to 2026-02-24\nTotal Applications:  147\nThird-Party Apps:    98\nFirst-Party Apps:    49\n\nPERMISSION INVENTORY\nTotal OAuth Grants:          487\n  Delegated Permissions:     312\n  Application Permissions:   175\n  Admin-Consented:           89\n  User-Consented:            223\n\nRISK CLASSIFICATION\nCritical Risk Apps:     7\n  - UnknownCRMApp (Mail.ReadWrite, Files.ReadWrite.All - UNAPPROVED)\n  - LegacySync (Directory.ReadWrite.All - EXCESSIVE)\n  - DevToolX (Application.ReadWrite.All - OVERLY BROAD)\nHigh Risk Apps:         18\nMedium Risk Apps:       34\nLow Risk Apps:          88\n\nFINDINGS\nUnapproved Applications:        12 (REVOKE IMMEDIATELY)\nExcessive Scopes:               23 apps with scopes beyond approved list\nOverly Broad Permissions:       15 apps that can be downgraded\nStale Grants (90+ days):        31 apps with no recent API activity\n\nREMEDIATION PLAN\nPriority 1 (Immediate):    12 unapproved app revocations\nPriority 2 (This Week):    23 excessive scope removals\nPriority 3 (This Month):   15 scope downgrades\nPriority 4 (Next Quarter): 31 stale grant revocations\n\nEstimated Scope Reduction:  34% of total permissions\n```\n",{"name":5,"tags":57,"author":62,"domain":45,"license":15,"version":63,"mitre_f3":64,"nist_csf":90,"subdomain":95,"description":96,"mitre_attack":97},[32,58,59,60,38,61],"scope-minimization","API-security","consent-review","token-audit","mahipal","1.0",{"tactics":65,"version":68,"techniques":69},[40,66,67],"positioning","stealth","1.1",[70,74,78,81,84,87],{"id":71,"name":72,"source":73,"tactic":40},"T1550.001","Use Alternate Authentication Material: Application Access Token","attack",{"id":75,"name":76,"source":77,"tactic":40},"F1006.001","Account Takeover: Exposed API Key","f3",{"id":79,"name":80,"source":77,"tactic":40},"F1004","Access with Stolen Session Cookie",{"id":82,"name":83,"source":77,"tactic":66},"F1005.001","Account Manipulation: Account Linking",{"id":85,"name":86,"source":73,"tactic":66},"T1539","Steal Web Session Cookie",{"id":88,"name":89,"source":77,"tactic":67},"F1023","Device Fingerprint Spoofing",[91,92,93,94],"PR.AA-01","PR.AA-02","PR.AA-05","PR.AA-06","identity-access-management","Performs OAuth 2.0 scope minimization review to identify over-permissioned third-party application integrations, excessive API scopes, unused token grants, and risky OAuth consent patterns across identity providers and SaaS platforms. Activates for requests involving OAuth scope audit, API permission review, third-party app risk assessment, or consent grant minimization.\n",[98,99,100,101],"T1078","T1110","T1556","T1098","main","54a798831d2266a3ca61ce68a7acb80b81160d57","skills\u002Fperforming-oauth-scope-minimization-review",4395,"https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills","https:\u002F\u002Fmahipal.engineer\u002FAnthropic-Cybersecurity-Skills\u002F","https:\u002F\u002Fgithub.com\u002Fmukul975","Mahipal.engineer","🔐 Cybersecurity | 💻 Dev | 📷 Street Photographer\r\n🎓 MSc | 📚 Research & AI Security","2026-08-31 12:32:44",{"source":8,"skillName":5,"commands":113,"prompt":123,"zipAvailable":124},[114,117,120],{"tool":115,"command":116},"npx","npx skills add mukul975\u002FAnthropic-Cybersecurity-Skills --skill performing-oauth-scope-minimization-review",{"tool":118,"command":119},"bunx","bunx skills add mukul975\u002FAnthropic-Cybersecurity-Skills --skill performing-oauth-scope-minimization-review",{"tool":121,"command":122},"pnpm","pnpm dlx skills add mukul975\u002FAnthropic-Cybersecurity-Skills --skill performing-oauth-scope-minimization-review","安装技能，技能地址：https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fperforming-oauth-scope-minimization-review\u002FSKILL.md",true,[126,131,137],{"path":127,"resourceType":127,"resourceTypeDesc":128,"sizeBytes":129,"sourceHtmlUrl":130},"LICENSE","许可证",11255,"https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fperforming-oauth-scope-minimization-review\u002FLICENSE",{"path":132,"resourceType":133,"resourceTypeDesc":134,"sizeBytes":135,"sourceHtmlUrl":136},"references\u002Fapi-reference.md","REFERENCE","参考文档",1968,"https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fperforming-oauth-scope-minimization-review\u002Freferences\u002Fapi-reference.md",{"path":138,"resourceType":139,"resourceTypeDesc":140,"sizeBytes":141,"sourceHtmlUrl":142},"scripts\u002Fagent.py","SCRIPT","脚本",7387,"https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fperforming-oauth-scope-minimization-review\u002Fscripts\u002Fagent.py",[144,168,192,219,245,270],{"skillNo":145,"name":146,"nameZh":6,"description":147,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":148,"categories":149,"keywords":151,"publishedAt":52},"01M6AGDM3HJXTKXX15ZZ0ZVCJ3","verifying-build-provenance-with-slsa-sigstore","Verifies artifact signatures and SLSA provenance using Sigstore's cosign (verify, verify-attestation, verify-blob-attestation) and slsa-verifier (verify-artifact), enforcing keyless OIDC builder identity and source repo against SLSA Build levels. Use in CI\u002FCD before deploying artifacts, when consuming third-party attestations, establishing a SLSA Build L3 pipeline, or confirming provenance during incident response or admission control.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fverifying-build-provenance-with-slsa-sigstore\u002FSKILL.md",[150],{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[152,153,154,155,36,45,156,44,50,157,158,159,160,161,162,163,164,165,166,167],"sigstore","provenance","slsa","verifying build provenance with slsa sigstore","incident response","code","artifacts","ci","supply-chain","pipeline","supply-chain-security","t1195","attestation","code-signing","cosign","keyless",{"skillNo":169,"name":170,"nameZh":6,"description":171,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":172,"categories":173,"keywords":175,"publishedAt":52},"01M6AGDGBPWYVZ2F11GFKJ4HZ9","validating-tpm-measured-boot-attestation","Verifies TPM 2.0 measured-boot integrity and remote attestation with tpm2-tools -- reading PCRs (tpm2_pcrread), replaying the boot event log, generating and checking signed quotes (tpm2_quote\u002Ftpm2_checkquote), and sealing secrets to a PCR policy. Use to confirm a system booted trusted firmware\u002Fkernel for Zero Trust device posture, detect boot-chain tampering via PCR drift, or build a golden-value baseline for fleet attestation.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fvalidating-tpm-measured-boot-attestation\u002FSKILL.md",[174],{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[176,164,177,178,36,179,45,50,180,181,182,183,184,185,186,187,188,189,190,191],"boot","TPM","validating tpm measured boot attestation","policy","verification","ZeRO","firmware","Tools","measured-boot","PCR","integrity","secrets","remote-attestation","tpm2-tools","integrity-verification","trusted-computing",{"skillNo":193,"name":194,"nameZh":6,"description":195,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":196,"categories":197,"keywords":202,"publishedAt":52},"01M6AGDCW0Y4FXZ3362GT1941M","validating-backup-integrity-for-recovery","Validates backup integrity through cryptographic hash verification, automated restore testing, corruption detection, and recoverability checks to confirm backups are reliable for disaster recovery and ransomware response. Use before relying on backups for recovery, when building post-backup validation pipelines, auditing backup infrastructure for compliance, or checking immutable\u002Fair-gapped backups for silent corruption or tampering.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Fvalidating-backup-integrity-for-recovery\u002FSKILL.md",[198,201],{"categoryNo":199,"categoryName":200,"taxonomyType":21,"taxonomyTypeDesc":22},"01JBSEEDCAT000000000000008","测试与质量",{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[186,203,204,205,206,45,207,208,180,209,210,211,212,213,214,35,215,216,217,218],"backup","recovery","validating backup integrity for recovery","testing","infrastructure","validation","compliance","hash-verification","incident-response","ransomware","cryptocurrency","detection","t1490","immutable","disaster-recovery","restore-testing",{"skillNo":220,"name":221,"nameZh":6,"description":222,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":223,"categories":224,"keywords":226,"publishedAt":52},"01M6AGD9GBG2KZ336AE763J3WH","triaging-windows-with-kape","Runs KAPE (Kroll Artifact Parser and Extractor) to collect targeted forensic artifacts (registry hives, $MFT, event logs, prefetch, browser data) via Targets and parse them with Modules wrapping Eric Zimmerman's EZ Tools (PECmd, MFTECmd, RECmd). Use during early incident containment\u002Ftriage when full disk imaging is impractical but a defensible, parseable Windows artifact set is needed quickly, including at-scale remote collection.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Ftriaging-windows-with-kape\u002FSKILL.md",[225],{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[227,228,229,45,230,231,232,233,234,235,236,237,238,239,240,241,183,242,243,244],"windows","kape","triaging windows with kape","registry","browser","logs","windows-forensics","dfir","mft","mftecmd","data","prefetch","eric-zimmerman","digital-forensics","SET","collection","pecmd","artifact-collection",{"skillNo":246,"name":247,"nameZh":6,"description":248,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":249,"categories":250,"keywords":252,"publishedAt":52},"01M6AGD5PW5J4EVZM958WD74ZQ","triaging-vulnerabilities-with-ssvc-framework","Triages and prioritizes vulnerabilities with CISA's Stakeholder-Specific Vulnerability Categorization (SSVC) decision tree, weighing exploitation status (via the CISA KEV catalog and FIRST EPSS API), technical impact, automatability, and mission prevalence to output Track\u002FTrack*\u002FAttend\u002FAct decisions. Use when prioritizing vulnerability scan results (OpenVAS, Nessus, Qualys) for remediation planning beyond raw CVSS scores.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Ftriaging-vulnerabilities-with-ssvc-framework\u002FSKILL.md",[251],{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[253,254,255,45,256,257,258,259,260,261,262,263,264,265,42,266,37,267,268,269],"vulnerabilities","framework","triaging vulnerabilities with ssvc framework","status","planning","CISA","vulnerability-management","risk-management","nessus","qualys","openvas","cvss","remediation","vulnerability","prioritization","ssvc","decision-tree",{"skillNo":271,"name":272,"nameZh":6,"description":273,"descriptionZh":6,"repositoryFullName":8,"ownerLogin":9,"ownerAvatarUrl":10,"ownerAccountNo":11,"ownerDisplayName":12,"repositoryNo":13,"starsCount":14,"licenseSpdxId":15,"licenseFileUrl":6,"sourceHtmlUrl":274,"categories":275,"keywords":277,"publishedAt":52},"01M6AGD24TTQQM4CXG69E3B9TJ","triaging-security-incident","Performs initial triage of security incidents using the NIST SP 800-61r3 and SANS PICERL frameworks, classifying incident type, assigning priority by business impact, and routing to the appropriate response team. Use when a SIEM\u002FEDR alert needs human classification, concurrent alerts must be prioritized, or a user report or threat-intel IOC match requires initial incident categorization.","https:\u002F\u002Fgithub.com\u002Fmukul975\u002FAnthropic-Cybersecurity-Skills\u002Fblob\u002Fmain\u002Fskills\u002Ftriaging-security-incident\u002FSKILL.md",[276],{"categoryNo":24,"categoryName":25,"taxonomyType":21,"taxonomyTypeDesc":22},[36,278,45,279,280,281,282,283,284,285,286,35,287,215,288,289,290,291,292,293],"triaging security incident","siem","file","ioc","soc","NIST-800-61","NIST","severity","edr","execution","analysis","classification","severity-classification","incident-triage","SANS-PICERL","SOC-operations"]