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.
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History
Fri, 20 Dec 2024 18:15:00 +0000
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cvssV3_1
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Thu, 19 Dec 2024 18:45:00 +0000
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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. | |
Title | Algorithm Confusion Vulnerability in cjwt | |
Weaknesses | CWE-347 | |
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cvssV4_0
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MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published: 2024-12-19T18:22:33.901Z
Updated: 2024-12-20T17:34:34.675Z
Reserved: 2024-11-29T18:02:16.756Z
Link: CVE-2024-54150
Vulnrichment
Updated: 2024-12-20T17:34:23.982Z
NVD
Status : Received
Published: 2024-12-19T19:15:07.747
Modified: 2024-12-20T18:15:29.847
Link: CVE-2024-54150
Redhat
No data.