xmidt-org cjwt up to 2.2.x JSON Web Token alg signature verification

Summaryinfo

A vulnerability, which was classified as problematic, has been found in xmidt-org cjwt up to 2.2.x. Affected by this vulnerability is an unknown functionality of the component JSON Web Token Handler. This manipulation of the argument alg causes signature verification. This vulnerability appears as CVE-2024-54150. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in xmidt-org cjwt up to 2.2.x and classified as problematic. Affected by this vulnerability is an unknown functionality of the component JSON Web Token Handler. The manipulation of the argument alg with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2024-54150 since 11/29/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 2.3.0 eliminates this vulnerability.

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Productinfo

Vendor

• xmidt-org

Name

• cjwt

Version

• 2.0
• 2.1
• 2.2

Website

• Product: https://github.com/xmidt-org/cjwt/

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CPE 2.2info

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