Vulnerability CVE-2017-12972
Published: 2017-08-20

Description:
In Nimbus JOSE+JWT before 4.39, there is no integer-overflow check when converting length values from bytes to bits, which allows attackers to conduct HMAC bypass attacks by shifting Additional Authenticated Data (AAD) and ciphertext so that different plaintext is obtained for the same HMAC.

CVSS2 => (AV:N/AC:L/Au:N/C:N/I:P/A:N)

CVSS Base Score
Impact Subscore
Exploitability Subscore
5/10
2.9/10
10/10
Exploit range
Attack complexity
Authentication
Remote
Low
No required
Confidentiality impact
Integrity impact
Availability impact
None
Partial
None
Affected software
Connect2id -> Nimbus jose+jwt 

 References:
https://bitbucket.org/connect2id/nimbus-jose-jwt/commits/0d2bd649ea386539220d4facfe1f65eb1dadb86c
https://bitbucket.org/connect2id/nimbus-jose-jwt/issues/224/byte-to-bit-overflow-in-cbc
https://bitbucket.org/connect2id/nimbus-jose-jwt/src/master/CHANGELOG.txt
Copyright 2024, cxsecurity.com

 

Back to Top