AI System Admin WordPress Plugin Security Review

Key Security Features

• Fail-Closed Architecture — Default deny and explicit allow only
• 7-Gate Permission System — Multiple independent security checks
• Full OAuth 2.0 Compliance — PKCE, refresh tokens, and revocation
• AES-256-CBC Token Encryption — Industry-standard cryptography
• Scope-Based Access Control — Granular permission model
• OAuth Isolation — Prevents tokens from accessing WordPress core API
• Comprehensive Audit Logging — Full transparency
• Rate Limiting — Prevents abuse

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OAuth 2.0 Security Architecture

Authentication Flow

The plugin implements an OAuth 2.0 flow initiated in Claude Desktop. When a user authorizes access:

1. The browser redirects to WordPress’s authorize endpoint.
2. The user approves scopes in the WordPress admin interface.
3. WordPress issues a 10-minute authorization code.
4. Claude Desktop exchanges the code for access (1 hr) and refresh (30 days) tokens using PKCE verification.
5. Tokens are encrypted with AES-256-CBC before storage.

Security strengths include:

• Mandatory PKCE (prevents code interception)
• Short-lived access tokens
• Single-use authorization codes
• CSRF protection via state parameter
• Redirect URI validation

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Scope System

Six distinct scopes define access levels:

Scope	Risk Level	Access
read	Low	File system (read_file, list_files, search_files)
database	Low–Medium	SELECT-only queries
memory	Low	Isolated storage
abilities	Medium–High	WordPress abilities
admin	Critical	Wildcard full access
claudeai	Critical	Full MCP access

Scopes are validated at authorization, token creation, execution, and MCP server level—a true defense-in-depth model.

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Token Encryption

Algorithm: AES-256-CBC
Key Derivation: PBKDF2-SHA256 (10,000 iterations)
Key Material: WordPress salts (AUTH_KEY, SECURE_AUTH_KEY, LOGGED_IN_KEY, NONCE_KEY)
Format: v1:base64(IV + ciphertext)

Uses a unique IV per encryption, timing-safe comparisons, and versioning for future upgrades.

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Critical Security Feature: OAuth Token Isolation

Unlike standard WordPress authentication, OAuth tokens never call wp_set_current_user().
They only access plugin-specific endpoints—never core WordPress APIs.

Result:

• No access to admin panels
• No privilege escalation or lateral movement

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Ability Permissions System

7-Gate Security Model

Each ability execution must pass through seven independent gates:

1. Abilities API enabled?
2. Ability registered in WordPress?
3. Listed in permission registry?
4. Admin enabled?
5. Rate limits satisfied?
6. User capability valid?
7. (Critical only) Admin approval present?

Default = DENY.
Every denial is logged with detailed reasons.

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Permission Database Schema

Dedicated database table includes:

• Ability name (unique, indexed)
• Enabled status & risk level
• Rate limits (per day/hour)
• Approval requirements (user/admin)
• WordPress capability required
• Custom validator function
• Audit trail (execution count, timestamp)

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Rate Limiting

Per-ability limits (daily + hourly) enforced via database queries.
Strengths:

• Fine-grained control
• Accurate counters

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Input Validation

Each permission can define a custom validator function, enforcing a fail-fast approach.
Validation occurs before execution and is fully logged.

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Risk Level System

Level	Description	Approval
Low	Read-only (no side effects)	User approval
Medium	Reversible writes (e.g., send-email)	User approval
High	Significant writes (e.g., update-settings)	User + higher limits
Critical	Destructive actions (e.g., delete-user, SQL)	Real-time admin approval

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Security Audit Logs

Logging Architecture

Logs record:

• Permission checks (allowed/denied)
• Ability executions
• OAuth authorization events
• Token generation, refresh, revocation
• Rate limit violations
• MCP tool executions

Every event includes user, IP, timestamp, and reason. Logs are accessible via the WordPress admin.

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Threat Model Analysis

1. Stolen OAuth Token

• Risk: Low
• Mitigation: Short expiration (1 hr), scoped tokens, no core API access, rate limits, full logging

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2. Malicious Ability Registration

• Risk: Medium
• Mitigation: Admin-only registration, approval with reasoning, full logging

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3. Rate Limit Bypass

• Risk: Low
• Mitigation: Database-enforced rate limits, per-ability counters

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4. Scope Escalation

• Risk: Very Low
• Mitigation: Cryptographically embedded scopes, validation on every tool call

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Conclusion

The AI System Admin Plugin showcases security architecture built with defense-in-depth principles.

Highlights:

• Fail-Closed Permission Model
• OAuth Token Isolation
• Comprehensive Logging
• Granular Scopes and Validation

The standout achievement is OAuth token isolation, which prevents WordPress core access and drastically reduces potential attack surface.