Security Review Skill

Identify exploitable security vulnerabilities in code. Report only HIGH CONFIDENCE findings—clear vulnerable patterns with attacker-controlled input.

Scope: Research vs. Reporting

CRITICAL DISTINCTION:

• Report on: Only the specific file, diff, or code provided by the user

• Research: The ENTIRE codebase to build confidence before reporting

Before flagging any issue, you MUST research the codebase to understand:

• Where does this input actually come from? (Trace data flow)

• Is there validation/sanitization elsewhere?

• How is this configured? (Check settings, config files, middleware)

• What framework protections exist?

Do NOT report issues based solely on pattern matching. Investigate first, then report only what you're confident is exploitable.

Confidence Levels

Level Criteria Action

HIGH Vulnerable pattern + attacker-controlled input confirmed Report with severity

MEDIUM Vulnerable pattern, input source unclear Note as "Needs verification"

LOW Theoretical, best practice, defense-in-depth Do not report

Do Not Flag

General Rules

• Test files (unless explicitly reviewing test security)

• Dead code, commented code, documentation strings

• Patterns using constants or server-controlled configuration

• Code paths that require prior authentication to reach (note the auth requirement instead)

Server-Controlled Values (NOT Attacker-Controlled)

These are configured by operators, not controlled by attackers:

Source Example Why It's Safe

Django settings settings.API_URL , settings.ALLOWED_HOSTS

Set via config/env at deployment

Environment variables os.environ.get('DATABASE_URL')

Deployment configuration

Config files config.yaml , app.config['KEY']

Server-side files

Framework constants django.conf.settings.*

Not user-modifiable

Hardcoded values BASE_URL = "https://api.internal"

Compile-time constants

SSRF Example - NOT a vulnerability:

SAFE: URL comes from Django settings (server-controlled)

response = requests.get(f"{settings.SEER_AUTOFIX_URL}{path}")

SSRF Example - IS a vulnerability:

VULNERABLE: URL comes from request (attacker-controlled)

response = requests.get(request.GET.get('url'))

Framework-Mitigated Patterns

Check language guides before flagging. Common false positives:

Pattern Why It's Usually Safe

Django {{ variable }}

Auto-escaped by default

React {variable}

Auto-escaped by default

Vue {{ variable }}

Auto-escaped by default

User.objects.filter(id=input)

ORM parameterizes queries

cursor.execute("...%s", (input,))

Parameterized query

innerHTML = "<b>Loading...</b>"

Constant string, no user input

Only flag these when:

• Django: {{ var|safe }} , {% autoescape off %} , mark_safe(user_input)

• React: dangerouslySetInnerHTML={{__html: userInput}}

• Vue: v-html="userInput"

• ORM: .raw() , .extra() , RawSQL() with string interpolation

Review Process

1. Detect Context

What type of code am I reviewing?

Code Type Load These References

API endpoints, routes authorization.md , authentication.md , injection.md

Frontend, templates xss.md , csrf.md

File handling, uploads file-security.md

Crypto, secrets, tokens cryptography.md , data-protection.md

Data serialization deserialization.md

External requests ssrf.md

Business workflows business-logic.md

GraphQL, REST design api-security.md

Config, headers, CORS misconfiguration.md

CI/CD, dependencies supply-chain.md

Error handling error-handling.md

Audit, logging logging.md

2. Load Language Guide

Based on file extension or imports:

Indicators Guide

.py , django , flask , fastapi

languages/python.md

.js , .ts , express , react , vue , next

languages/javascript.md

.go , go.mod

languages/go.md

.rs , Cargo.toml

languages/rust.md

.java , spring , @Controller

languages/java.md

3. Load Infrastructure Guide (if applicable)

File Type Guide

Dockerfile , .dockerignore

infrastructure/docker.md

K8s manifests, Helm charts infrastructure/kubernetes.md

.tf , Terraform infrastructure/terraform.md

GitHub Actions, .gitlab-ci.yml

infrastructure/ci-cd.md

AWS/GCP/Azure configs, IAM infrastructure/cloud.md

4. Research Before Flagging

For each potential issue, research the codebase to build confidence:

• Where does this value actually come from? Trace the data flow.

• Is it configured at deployment (settings, env vars) or from user input?

• Is there validation, sanitization, or allowlisting elsewhere?

• What framework protections apply?

Only report issues where you have HIGH confidence after understanding the broader context.

5. Verify Exploitability

For each potential finding, confirm:

Is the input attacker-controlled?

Attacker-Controlled (Investigate) Server-Controlled (Usually Safe)

request.GET , request.POST , request.args

settings.X , app.config['X']

request.json , request.data , request.body

os.environ.get('X')

request.headers (most headers) Hardcoded constants

request.cookies (unsigned) Internal service URLs from config

URL path segments: /users/<id>/

Database content from admin/system

File uploads (content and names) Signed session data

Database content from other users Framework settings

WebSocket messages

Does the framework mitigate this?

• Check language guide for auto-escaping, parameterization

• Check for middleware/decorators that sanitize

Is there validation upstream?

• Input validation before this code

• Sanitization libraries (DOMPurify, bleach, etc.)

6. Report HIGH Confidence Only

Skip theoretical issues. Report only what you've confirmed is exploitable after research.

Severity Classification

Severity Impact Examples

Critical Direct exploit, severe impact, no auth required RCE, SQL injection to data, auth bypass, hardcoded secrets

High Exploitable with conditions, significant impact Stored XSS, SSRF to metadata, IDOR to sensitive data

Medium Specific conditions required, moderate impact Reflected XSS, CSRF on state-changing actions, path traversal

Low Defense-in-depth, minimal direct impact Missing headers, verbose errors, weak algorithms in non-critical context

Quick Patterns Reference

Always Flag (Critical)

eval(user_input) # Any language exec(user_input) # Any language pickle.loads(user_data) # Python yaml.load(user_data) # Python (not safe_load) unserialize($user_data) # PHP deserialize(user_data) # Java ObjectInputStream shell=True + user_input # Python subprocess child_process.exec(user) # Node.js

Always Flag (High)

innerHTML = userInput # DOM XSS dangerouslySetInnerHTML={user} # React XSS v-html="userInput" # Vue XSS f"SELECT * FROM x WHERE {user}" # SQL injection SELECT * FROM x WHERE ${user} # SQL injection os.system(f"cmd {user_input}") # Command injection

Always Flag (Secrets)

password = "hardcoded" api_key = "sk-..." AWS_SECRET_ACCESS_KEY = "..." private_key = "-----BEGIN"

Check Context First (MUST Investigate Before Flagging)

SSRF - ONLY if URL is from user input, NOT from settings/config

requests.get(request.GET['url']) # FLAG: User-controlled URL requests.get(settings.API_URL) # SAFE: Server-controlled config requests.get(f"{settings.BASE}/{x}") # CHECK: Is 'x' user input?

Path traversal - ONLY if path is from user input

open(request.GET['file']) # FLAG: User-controlled path open(settings.LOG_PATH) # SAFE: Server-controlled config open(f"{BASE_DIR}/{filename}") # CHECK: Is 'filename' user input?

Open redirect - ONLY if URL is from user input

redirect(request.GET['next']) # FLAG: User-controlled redirect redirect(settings.LOGIN_URL) # SAFE: Server-controlled config

Weak crypto - ONLY if used for security purposes

hashlib.md5(file_content) # SAFE: File checksums, caching hashlib.md5(password) # FLAG: Password hashing random.random() # SAFE: Non-security uses (UI, sampling) random.random() for token # FLAG: Security tokens need secrets module

Output Format

Security Review: [File/Component Name]

Summary

• Findings: X (Y Critical, Z High, ...)
• Risk Level: Critical/High/Medium/Low
• Confidence: High/Mixed

Findings

[VULN-001] [Vulnerability Type] (Severity)

• Location: file.py:123
• Confidence: High
• Issue: [What the vulnerability is]
• Impact: [What an attacker could do]
• Evidence:

  [Vulnerable code snippet]
  
  

• Fix: [How to remediate]

Needs Verification

[VERIFY-001] [Potential Issue]

• Location: file.py:456

• Question: [What needs to be verified]

If no vulnerabilities found, state: "No high-confidence vulnerabilities identified."

Reference Files

Core Vulnerabilities (references/)

Language Guides (languages/)

• python.md - Django, Flask, FastAPI patterns
• javascript.md - Node, Express, React, Vue, Next.js
• go.md - Go-specific security patterns
• rust.md - Rust unsafe blocks, FFI security
• java.md - Spring, Java EE patterns

Infrastructure (infrastructure/)

• docker.md - Container security
• kubernetes.md - K8s RBAC, secrets, policies
• terraform.md - IaC security
• ci-cd.md - Pipeline security
• cloud.md - AWS/GCP/Azure security