Formbricks is an open source qualtrics alternative. Prior to version 4.0.1, Formbricks is missing JWT signature verification. This vulnerability stems from a token validation routine that only decodes JWTs (jwt.decode) without verifying their signatures.
Both the email verification token login path and the password reset server action use the same validator, which does not check the token’s signature, expiration, issuer, or audience. If an attacker learns the victim’s actual user.id, they can craft an arbitrary JWT with an alg: "none" header and use it to authenticate and reset the victim’s password. This issue has been patched in version 4.0.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/formbricks/formbricks/blob/843110b0d6c37b5c0da54291616f84c91…
security-advisories@github.com
https://github.com/formbricks/formbricks/commit/eb1349f205189d5b2d4a95ec42245ca…
security-advisories@github.com
https://github.com/formbricks/formbricks/pull/6596
security-advisories@github.com
https://github.com/formbricks/formbricks/security/advisories/GHSA-7229-q9pv-j6p4
security-advisories@github.com