CVE-2023-37464: OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). The AES GCM decryption routine incorrectly uses the Tag...

Description

OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). The AES GCM decryption routine incorrectly uses the Tag length from the actual Authentication Tag provided in the JWE. The spec says that a fixed length of 16 octets must be applied. Therefore this bug allows an attacker to provide a truncated Authentication Tag and to modify the JWE accordingly. Users should upgrade to a version >= 0.6.2.2. Users unable to upgrade should avoid using AES GCM encryption and replace it with another encryption algorithm (e.g. AES CBC).

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

0.60%

44.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-327

Affected Software

Vendor	Product	Versions
Cisco	Cjose	< 0.6.2.2

References

Timeline

Published: Jul 14, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-37464?

OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). The AES GCM decryption routine incorrectly uses the Tag length from the actual Authentication Tag provided in the JWE. The spec says that a fixed length of 16 octets must be applied. Therefore this bug allows an attacker to provide a truncated Authentication Tag and to modify the JWE accordingly. Users should upgrade to a version >= 0.6.2.2. Users unable to upgrade should avoid using AES GCM encryption and replace it with another encryption algorithm (e.g. AES CBC).

How severe is CVE-2023-37464?

CVE-2023-37464 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.60% probability of exploitation in the next 30 days.

How do I fix CVE-2023-37464?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.