Out-of-bounds read in OpenSC - CVE-2025-66037

Vulnerability details

The vulnerability allows an attacker with physical access to disclose sensitive information, modify data, or cause a denial of service.

The vulnerability exists due to out-of-bounds read in sc_pkcs15_pubkey_from_spki_fields() in the X.509/SPKI handling path when parsing malformed X.509 certificate or SPKI data via the PIV/PKCS#15 reader path. An attacker with physical access can feed specially crafted certificate data to trigger an out-of-bounds heap read and disclose sensitive information, modify data, or cause a denial of service.

The issue occurs when a zero-length buffer is allocated and one byte is read past the end of that allocation. It is reachable through the shared certificate and public-key decoding logic, including the fuzz_pkcs15_reader and fuzz_pkcs15_crypt harnesses, and was observed as undefined behavior in a non-sanitized build under Valgrind.

Affected software

How to mitigate CVE-2025-66037

External References

• https://github.com/OpenSC/OpenSC/security/advisories/GHSA-m58q-rmjm-mmfx

Related Security Bulletins

• Multiple vulnerabilities in OpenSC
• Fedora 44 update for opensc
• Fedora 43 update for opensc
• Fedora 42 update for opensc
• SUSE update for opensc
• Anolis OS update for opensc
• openEuler 24.03 LTS SP3 update for opensc
• openEuler 24.03 LTS SP1 update for opensc