security-audit

What this skill does

# Security Audit

Scan, detect, and fix security issues in codebases and infrastructure. Covers dependency vulnerabilities, secret detection, OWASP top 10, SSL/TLS verification, file permissions, and secure coding patterns.

## When to Use

- Scanning project dependencies for known vulnerabilities
- Detecting hardcoded secrets, API keys, or credentials in source code
- Reviewing code for OWASP top 10 vulnerabilities (injection, XSS, CSRF, etc.)
- Verifying SSL/TLS configuration for endpoints
- Auditing file and directory permissions
- Checking authentication and authorization patterns
- Preparing for a security review or compliance audit

## Dependency Vulnerability Scanning

### Node.js

```bash
# Built-in npm audit
npm audit
npm audit --json | jq '.vulnerabilities | to_entries[] | {name: .key, severity: .value.severity, via: .value.via[0]}'

# Fix automatically where possible
npm audit fix

# Show only high and critical
npm audit --audit-level=high

# Check a specific package
npm audit --package-lock-only

# Alternative: use npx to scan without installing
npx audit-ci --high
```

### Python

```bash
# pip-audit (recommended)
pip install pip-audit
pip-audit
pip-audit -r requirements.txt
pip-audit --format=json

# safety (alternative)
pip install safety
safety check
safety check -r requirements.txt --json

# Check a specific package
pip-audit --requirement=- <<< "requests==2.25.0"
```

### Go

```bash
# Built-in vuln checker
go install golang.org/x/vuln/cmd/govulncheck@latest
govulncheck ./...

# Check specific binary
govulncheck -mode=binary ./myapp
```

### Rust

```bash
# cargo-audit
cargo install cargo-audit
cargo audit

# With fix suggestions
cargo audit fix
```

### Universal: Trivy (scans any project)

```bash
# Install: https://aquasecurity.github.io/trivy
# Scan filesystem
trivy fs .

# Scan specific language
trivy fs --scanners vuln --severity HIGH,CRITICAL .

# Scan Docker image
trivy image myapp:latest

# JSON output
trivy fs --format json -o results.json .
```

## Secret Detection

### Manual grep patterns

```bash
# AWS keys
grep -rn 'AKIA[0-9A-Z]\{16\}' --include='*.{js,ts,py,go,java,rb,env,yml,yaml,json,xml,cfg,conf,ini}' .

# Generic API keys and tokens
grep -rn -i 'api[_-]\?key\|api[_-]\?secret\|access[_-]\?token\|auth[_-]\?token\|bearer ' \
  --include='*.{js,ts,py,go,java,rb,env,yml,yaml,json}' .

# Private keys
grep -rn 'BEGIN.*PRIVATE KEY' .

# Passwords in config
grep -rn -i 'password\s*[:=]' --include='*.{env,yml,yaml,json,xml,cfg,conf,ini,toml}' .

# Connection strings with credentials
grep -rn -i 'mongodb://\|mysql://\|postgres://\|redis://' --include='*.{js,ts,py,go,env,yml,yaml,json}' . | grep -v 'localhost\|127.0.0.1\|example'

# JWT tokens (three base64 segments separated by dots)
grep -rn 'eyJ[A-Za-z0-9_-]*\.eyJ[A-Za-z0-9_-]*\.' --include='*.{js,ts,py,go,log,json}' .
```

### Automated scanning with git

```bash
# Scan git history for secrets (not just current files)
# Using git log + grep
git log -p --all | grep -n -i 'api.key\|password\|secret\|token' | head -50

# Check staged files before commit
git diff --cached --name-only | xargs grep -l -i 'api.key\|password\|secret\|token' 2>/dev/null
```

### Pre-commit hook for secrets

```bash
#!/bin/bash
# .git/hooks/pre-commit - Block commits containing potential secrets

PATTERNS=(
    'AKIA[0-9A-Z]{16}'
    'BEGIN.*PRIVATE KEY'
    'password\s*[:=]\s*["\x27][^"\x27]+'
    'api[_-]?key\s*[:=]\s*["\x27][^"\x27]+'
    'sk-[A-Za-z0-9]{20,}'
    'ghp_[A-Za-z0-9]{36}'
    'xox[bpoas]-[A-Za-z0-9-]+'
)

STAGED_FILES=$(git diff --cached --name-only --diff-filter=ACM)
[ -z "$STAGED_FILES" ] && exit 0

EXIT_CODE=0
for pattern in "${PATTERNS[@]}"; do
    matches=$(echo "$STAGED_FILES" | xargs grep -Pn "$pattern" 2>/dev/null)
    if [ -n "$matches" ]; then
        echo "BLOCKED: Potential secret detected matching pattern: $pattern"
        echo "$matches"
        EXIT_CODE=1
    fi
done

if [ $EXIT_CODE -ne 0 ]; then
    echo ""
    echo "To proceed anyway: git commit --no-verify"
    echo "To remove secrets: replace with environment variables"
fi
exit $EXIT_CODE
```

### .gitignore audit

```bash
# Check if sensitive files are tracked
echo "--- Files that should probably be gitignored ---"
for pattern in '.env' '.env.*' '*.pem' '*.key' '*.p12' '*.pfx' 'credentials.json' \
               'service-account*.json' '*.keystore' 'id_rsa' 'id_ed25519'; do
    found=$(git ls-files "$pattern" 2>/dev/null)
    [ -n "$found" ] && echo "  TRACKED: $found"
done

# Check if .gitignore exists and has common patterns
if [ ! -f .gitignore ]; then
    echo "WARNING: No .gitignore file found"
else
    for entry in '.env' 'node_modules' '*.key' '*.pem'; do
        grep -q "$entry" .gitignore || echo "  MISSING from .gitignore: $entry"
    done
fi
```

## OWASP Top 10 Code Patterns

### 1. Injection (SQL, Command, LDAP)

```bash
# SQL injection: string concatenation in queries
grep -rn "query\|execute\|cursor" --include='*.{py,js,ts,go,java,rb}' . | \
  grep -i "f\"\|format(\|%s\|\${\|+ \"\|concat\|sprintf" | \
  grep -iv "parameterized\|placeholder\|prepared"

# Command injection: user input in shell commands
grep -rn "exec(\|spawn(\|system(\|popen(\|subprocess\|os\.system\|child_process" \
  --include='*.{py,js,ts,go,java,rb}' .

# Check for parameterized queries (good)
grep -rn "\\$[0-9]\|\\?\|%s\|:param\|@param\|prepared" --include='*.{py,js,ts,go,java,rb}' .
```

### 2. Broken Authentication

```bash
# Weak password hashing (MD5, SHA1 used for passwords)
grep -rn "md5\|sha1\|sha256" --include='*.{py,js,ts,go,java,rb}' . | grep -i "password\|passwd"

# Hardcoded credentials
grep -rn -i "admin.*password\|password.*admin\|default.*password" \
  --include='*.{py,js,ts,go,java,rb,yml,yaml,json}' .

# Session tokens in URLs
grep -rn "session\|token\|jwt" --include='*.{py,js,ts,go,java,rb}' . | grep -i "url\|query\|param\|GET"

# Check for rate limiting on auth endpoints
grep -rn -i "rate.limit\|throttle\|brute" --include='*.{py,js,ts,go,java,rb}' .
```

### 3. Cross-Site Scripting (XSS)

```bash
# Unescaped output in templates
grep -rn "innerHTML\|dangerouslySetInnerHTML\|v-html\|\|html(" \
  --include='*.{js,ts,jsx,tsx,vue,html}' .

# Template injection
grep -rn "{{{.*}}}\|<%=\|<%-\|\$\!{" --include='*.{html,ejs,hbs,pug,erb}' .

# Document.write
grep -rn "document\.write\|document\.writeln" --include='*.{js,ts,html}' .

# eval with user input
grep -rn "eval(\|new Function(\|setTimeout.*string\|setInterval.*string" \
  --include='*.{js,ts}' .
```

### 4. Insecure Direct Object References

```bash
# Direct ID usage in routes without authz check
grep -rn "params\.id\|params\[.id.\]\|req\.params\.\|request\.args\.\|request\.GET\." \
  --include='*.{py,js,ts,go,java,rb}' . | \
  grep -i "user\|account\|profile\|order\|document"
```

### 5. Security Misconfiguration

```bash
# CORS wildcard
grep -rn "Access-Control-Allow-Origin.*\*\|cors({.*origin.*true\|cors()" \
  --include='*.{py,js,ts,go,java,rb}' .

# Debug mode in production configs
grep -rn "DEBUG\s*=\s*True\|debug:\s*true\|NODE_ENV.*development" \
  --include='*.{py,js,ts,yml,yaml,json,env}' .

# Verbose error messages exposed to clients
grep -rn "stack\|traceback\|stackTrace" --include='*.{py,js,ts,go,java,rb}' . | \
  grep -i "response\|send\|return\|res\."
```

## SSL/TLS Verification

### Check endpoint SSL

```bash
# Full SSL check
openssl s_client -connect example.com:443 -servername example.com < /dev/null 2>/dev/null | \
  openssl x509 -noout -subject -issuer -dates -fingerprint

# Check certificate expiry
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | \
  openssl x509 -noout -enddate

# Check supported TLS versions
for v in tls1 tls1_1 tls1_2 tls1_3; do
  result=$(openssl s_client -connect example.com:443 -$v < /dev/null 2>&1)
  if echo "$result" | grep -q "Cipher is"; then
    echo "$v: SUPPORTED"
  else
    echo "$v: NOT SUPPORTED"
  fi
done

# Check cipher suites
openssl s_client -connect example.