CVE-2023-40660 — A flaw was found in OpenSC packages that allow a potential PIN bypass

A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logo

01What is this vulnerability?

A flaw was found in OpenSC packages that allow a potential PIN bypass. When a token/card is authenticated by one process, it can perform cryptographic operations in other processes when an empty zero-length pin is passed. This issue poses a security risk, particularly for OS logon/screen unlock and for small, permanently connected tokens to computers. Additionally, the token can internally track…

02Affected products

Vendor	Product	Versions
?	?	0.17.0
Red Hat	Red Hat Enterprise Linux 8	0:0.20.0-7.el8_9
Red Hat	Red Hat Enterprise Linux 9	0:0.23.0-3.el9_3
Red Hat	Red Hat Enterprise Linux 7	unspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-11-06T16:58:42.939Z
• Last modified: 2025-11-06T22:59:00.695Z

09References

• access.redhat.com — https://access.redhat.com/errata/RHSA-2023:7876
• access.redhat.com — https://access.redhat.com/errata/RHSA-2023:7879
• access.redhat.com — https://access.redhat.com/security/cve/CVE-2023-40660
• bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=2240912
• github.com — https://github.com/OpenSC/OpenSC/issues/2792#issuecomment-1674806651
• github.com — https://github.com/OpenSC/OpenSC/releases/tag/0.24.0-rc1
• github.com — https://github.com/OpenSC/OpenSC/wiki/OpenSC-security-advisories