CVE-2023-40012
uthenticode EKU validation bypass
CVE-2023-40012 is a medium vulnerability (CVSS 5.9) in Trailofbits Uthenticode, published August 9, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.
- Severity
- 5.9 MediumCVSS 3.1, CVE List
- Exploit chance
- 0.25%EPSS, 16th percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
Affected products
What each source reports
CVE List Score used 5.9
uthenticode EKU validation bypass
uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.
- Record
CVE-2023-40012- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-325, CWE-347
- Updated
- 2026-11-02
EUVDEUVD-2023-44635 5.9
uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.
- Record
EUVD-2023-44635- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-03
NVD 5.9
uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.
- Record
CVE-2023-40012- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-325, CWE-347
- Updated
- 2026-11-02
OSV 5.9
uthenticode EKU validation bypass
uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.
- Record
CVE-2023-40012- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-325, CWE-347
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
github.com/trailofbits/uthenticode/security/advisories/GHSA-gm2f-j4rj-6xqj
github.com/trailofbits/uthenticode/pull/78
github.com/trailofbits/uthenticode/commit/caeb1eb62412605f71bd96ce9bb9420644b6db53
github.com/CVEProject/cvelistV5/tree/main/cves/2023/40xxx/CVE-2023-40012.json
nvd.nist.gov/vuln/detail/CVE-2023-40012