AI Security Audit Checklist: 15 Vulnerabilities Claude Found in Production Code

Most web applications contain at least one vulnerability from the OWASP Top 10. A typical security audit takes 2-3 weeks and costs upward of $10,000. An LLM can compress the initial audit down to a few hours because it scans code for patterns rather than specific CVEs. Below are 15 vulnerabilities found while auditing production code with Claude. Each includes the vulnerable code, the fixed version, and a prompt to reproduce the finding. Classification follows OWASP Top 10 (2021). Order reflects frequency of occurrence: most common first. Methodology: how to run an AI security audit The audit consists of three passes. First, a broad scan: the LLM receives the entire project and looks for vulnerability patterns. Second, deep analysis: each identified pattern is verified in context (middleware, ORM, framework). Third, verification: manual review of every finding, because LLMs produce false positives. Prompt for the broad scan: Perform a security audit of this code. For each finding, include: 1. CWE ID and name 2. OWASP Top 10 category 3. Severity (Critical/High/Medium/Low) 4. The vulnerable code snippet 5. Attack vector -- exactly how an attacker would exploit this 6. Fixed code Ignore stylistic comments. Focus on security only. Start with injection attacks, then broken access control, then the rest. This prompt works because it defines the output structure and prioritizes categories. Without explicit instructions, the LLM mixes critical vulnerabilities with remarks about email validation. More on structured AI code review: AI Code Review Checklist . A03:2021 -- Injection 1. SQL Injection via string concatenation The most common finding. Shows up even in projects using an ORM, because developers switch to raw queries for complex filters. Vulnerable code: // API endpoint for user search app . get ( ' /api/users ' , async ( req , res ) => { const { search , sortBy } = req . query ; const query = ` SELECT id, name, email FROM users WHERE name LIKE '% ${ search } %' ORDER