Vulnerability Description
OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Opensc Project | Opensc | < 0.27.0 |
Related Weaknesses (CWE)
References
- https://github.com/OpenSC/OpenSC/commit/6db171bcb6fd7cb3b51098fefbb3b28e44f0a79cPatch
- https://github.com/OpenSC/OpenSC/security/advisories/GHSA-72x5-fwjx-2459ExploitVendor Advisory
- https://github.com/OpenSC/OpenSC/wiki/CVE-2025-66038Vendor Advisory
FAQ
What is CVE-2025-66038?
CVE-2025-66038 is a vulnerability with a CVSS score of 3.9 (LOW). OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (...
How severe is CVE-2025-66038?
CVE-2025-66038 has been rated LOW with a CVSS base score of 3.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66038?
Check the references section above for vendor advisories and patch information. Affected products include: Opensc Project Opensc.