mitm-find-auth

name: mitm-find-auth description: Find authentication and session vulnerabilities. Use when user asks about auth bypass, session issues, login security, or token problems.

Find Authentication Vulnerabilities

Analyze the mitmproxy dump (log.txt) for auth issues for: $ARGUMENTS

Requires: log.txt in the current directory. If it's missing, capture traffic first:

mitmdump --set flow_detail=3 2>&1 | tee log.txt

High-Value Auth Patterns (from 783 real HackerOne bounty reports)

1. Password Reset Token Issues

Real examples from bounties:

• Reset link not expiring after email change
• Reset token reusable multiple times
• Reset token valid after password change
• Predictable/sequential reset tokens

Search patterns:

grep -iE '(reset|forgot|recover|password).*token' log.txt
grep -iE 'token=[a-zA-Z0-9]{10,}' log.txt

2. Privilege Escalation via Role Manipulation

Real examples:

• Change role=user to role=admin in request
• Modify isAdmin=false to isAdmin=true
• Access admin endpoints with user token
• Send invites on behalf of other admins

Search patterns:

grep -iE '(role|permission|privilege|isAdmin|is_admin|user_type|account_type)[=:]["'\'']?\w+' log.txt

3. Comment/Action After Disable

Real examples:

• Edit comments after comments disabled on video
• Perform actions after account suspended
• Access resources after permission revoked

Search patterns:

grep -iE '(edit|update|delete|modify).*comment' log.txt
grep -iE 'action=(edit|delete|update)' log.txt

4. File/Resource Access Control

Real examples:

• Private file becomes public via transformation
• Access invoice documents without authorization
• Download private attachments with predictable URLs

Search patterns:

grep -iE '(download|file|document|attachment|invoice|receipt)' log.txt
grep -iE '\.(pdf|doc|xlsx?|csv)' log.txt

5. Session/Token Vulnerabilities

Patterns to check:

- Session token in URL (session_id=xxx in query params)
- JWT with weak/no signature (alg: none attack)
- Token doesn't change after password change
- Token valid after logout
- Predictable session tokens

Search patterns:

grep -iE 'session[_-]?(id|token)=' log.txt
grep -oE 'eyJ[a-zA-Z0-9_-]+\.eyJ[a-zA-Z0-9_-]+\.[a-zA-Z0-9_-]*' log.txt  # JWT

Vulnerability Categories & Severity

Testing Methodology

Step 1: Map Authentication Flows

# Find login/auth endpoints
grep -iE '(login|signin|authenticate|oauth|token|session)' log.txt

# Find logout endpoints
grep -iE '(logout|signout|revoke)' log.txt

# Find password flows
grep -iE '(password|reset|forgot|recover|change)' log.txt

Step 2: Analyze Token Structure

# Extract bearer tokens
grep -oE 'Bearer [a-zA-Z0-9._-]+' log.txt | sort -u

# Extract cookies
grep -oE 'Cookie:.*' log.txt | head -20

# Check for JWT
grep -oE 'eyJ[a-zA-Z0-9_-]+\.eyJ[a-zA-Z0-9_-]+' log.txt

Step 3: Test Token Validity

# Test if token works after logout (replay attack)
curl -H "Authorization: Bearer OLD_TOKEN" "https://target.com/api/profile"

# Test with modified role
curl -X POST "https://target.com/api/update" -d '{"role":"admin"}'

# Test admin endpoint with user token
curl -H "Authorization: Bearer USER_TOKEN" "https://target.com/api/admin/users"

Step 4: Check Password Reset Flow

# Test reset token reuse
curl "https://target.com/reset?token=USED_TOKEN"

# Test reset token after email change
# (token from old email should be invalid)

Real Attack Scenarios

Scenario 1: Account Takeover via Reset Token

1. Attacker requests password reset for victim
2. Victim changes email before using reset link
3. Old reset link still works → Attacker takes over account

Scenario 2: Privilege Escalation via Request Manipulation

1. User captures their profile update request
2. Adds "role": "admin" or "isAdmin": true
3. Server doesn't validate, grants admin access

Scenario 3: BOLA via Action Replay

1. User A creates comment on their post
2. User B captures edit request: POST /edit_comment?id=123
3. User B replays with different comment_id → edits User A's comment

Output Format

## AUTH Finding: [Brief Description]

**Endpoint**: `METHOD https://target.com/path`
**Type**: [Password Reset|Privilege Escalation|Session|Access Control]
**Severity**: [CRITICAL|HIGH|MEDIUM|LOW]

**Vulnerable Flow**:
1. Step one
2. Step two
3. Exploit step

**Evidence**:
[Request/response snippets]

**Impact**:
- Account takeover
- Unauthorized access
- Data exposure

**Test Command**:
curl -X METHOD 'https://target.com/...' -H '...'

**Remediation**:
- Invalidate tokens on sensitive actions
- Server-side role validation
- Rate limit sensitive endpoints

False Positives to Ignore

• Public endpoints that are intentionally unauthenticated
• Read-only public data endpoints
• Health check / status endpoints
• Static asset endpoints
• Endpoints that return generic errors for invalid tokens