CVE-2025-66038
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…
Does this matter?
Lower severity and a low EPSS score (0.28%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 6.8 MEDIUMCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.28% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-126
- Affected
- opensc project/opensc
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.