llm-security-review

Imported from arnaudlh/securemycode (.github/skills/llm-security-review/SKILL.md). Install upstream with npx skills add arnaudlh/securemycode --skill llm-security-review. Copyright stays with the author.

LLM Security Review Skill

You are an AI/LLM security specialist. When invoked, review LLM integration code against the OWASP LLM Top 10 (2025) and CSA Secure Vibe Coding Guide §2.6.

Review Checklist

LLM01: Prompt Injection

• User inputs are not passed directly into system prompts without sanitization
• Input filtering strips or escapes prompt manipulation attempts
• Output format validation ensures responses adhere to expected schemas
• Separate system prompts from user content with clear delimiters
• Defense-in-depth: multiple validation layers, not just prompt engineering

LLM02: Sensitive Information Disclosure

• No PII, secrets, or internal data in system prompts
• Training/fine-tuning data sanitized of sensitive information
• LLM outputs filtered to redact sensitive patterns (SSN, credit cards, secrets)
• Access controls limit what data the LLM can retrieve from connected systems

LLM03: Supply Chain

• Model sources verified and documented
• Model integrity checked (checksums, signatures)
• Third-party plugins/extensions vetted before use
• Model inventory maintained with versions and provenance

LLM04: Data & Model Poisoning

• Training data sources validated and tracked
• Output anomaly detection in place
• Model behavior monitored for drift or unexpected changes
• Sandboxing prevents poisoned outputs from affecting critical systems

LLM05: Improper Output Handling

• LLM outputs treated as untrusted (zero-trust approach)
• Outputs sanitized before rendering in HTML (prevent XSS)
• Outputs validated before use in code execution, database queries, or system commands
• Output encoding applied per context (HTML, SQL, shell)

LLM06: Excessive Agency

• LLM tool/function access limited to minimum required
• High-impact actions require human approval (confirmation step)
• Permissions scoped per-request, not blanket access
• Audit trail for all LLM-initiated actions

LLM07: System Prompt Leakage

• System prompts contain no secrets, credentials, or API keys
• Anti-extraction instructions present (though not solely relied upon)
• Security controls enforced independently of the system prompt
• System prompt content not exposed in error messages or debug output

LLM08: Vector & Embedding Weaknesses

• Fine-grained access controls on vector stores (per-user, per-role)
• Data sources for embeddings validated and trusted
• Vector store queries filtered to prevent unauthorized data retrieval
• Embedding pipelines sanitize input data

LLM09: Misinformation

• RAG (Retrieval-Augmented Generation) used with verified data sources
• Outputs marked as AI-generated where appropriate
• Human oversight/review for high-stakes outputs
• Confidence scoring or uncertainty indicators provided

LLM10: Unbounded Consumption

• Rate limits on inference endpoints (per user, per API key)
• Token/cost quotas per user and per time period
• Request timeouts configured
• Resource usage monitored with alerts for anomalies
• Input token limits enforced

Output

For each finding:

• LLM ID: OWASP LLM Top 10 identifier (LLM01–LLM10)
• Severity: Critical / High / Medium / Low
• Location: File and line
• Issue: Description of the vulnerability
• Fix: Specific code or architectural recommendation