CVE-2024-54150

Description

cjwt is a C JSON Web Token (JWT) Implementation. Algorithm confusion occurs when a system improperly verifies the type of signature used, allowing attackers to exploit the lack of distinction between signing methods. If the system doesn't differentiate between an HMAC signed token and an RS/EC/PS signed token during verification, it becomes vulnerable to this kind of attack. For instance, an attacker could craft a token with the alg field set to "HS256" while the server expects an asymmetric algorithm like "RS256". The server might mistakenly use the wrong verification method, such as using a public key as the HMAC secret, leading to unauthorised access. For RSA, the key can be computed from a few signatures. For Elliptic Curve (EC), two potential keys can be recovered from one signature. This can be used to bypass the signature mechanism if an application relies on asymmetrically signed tokens. This issue has been addressed in version 2.3.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Reserved 2024-11-29 | Published 2024-12-19 | Updated 2024-12-20 | Assigner GitHub_M

Problem types

CWE-347: Improper Verification of Cryptographic Signature

Product status

< 2.3.0
affected

References

github.com/...g/cjwt/security/advisories/GHSA-9h24-7qp5-gp82

github.com/...ommit/096ab3e37f73c914b716e7259589179f363265fd

cve.org (CVE-2024-54150)

nvd.nist.gov (CVE-2024-54150)

Download JSON