Vulnerability in Trailofbits Uthenticode

CVE-2023-39969

uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Version 1.0.9 of uthenticode hashed the entire file rather than hashing sections by virtual address, in violation of the Authenticode specification. As a result, an attacker could modify code within a binary without changing its Authenticode hash, making it appear valid from uthenticode's perspective. Versions of uthenticode prior to 1.0.9 are not vulnerable to this attack, nor are versions in the 2.x series. By design, uthenticode does not perform full-chain validation. However, the malleability of signature verification introduced in 1.0.9 was an unintended oversight. The 2.x series addresses the vulnerability. Versions prior to 1.0.9 are also not vulnerable, but users are encouraged to upgrade rather than downgrade. There are no workarounds to this vulnerability.

EPSS: 0.005 (37.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-39969?
CVE-2023-39969 is a critical-severity vulnerability in Trailofbits Uthenticode, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.0/10. Published 2023-08-09.
How severe is CVE-2023-39969?
Critical severity. CVSS v3 base score is 9.0 out of 10.