OpenSC: `sc_compacttlv_find_tag` can return out-of-bounds pointers_CVE-2025-66038

3.9 / 10

LOW

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

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.

Basic Information

ID CVE-2025-66038

Source GitHub_M

Published Mar 30, 2026 at 17:03

Modified Apr 1, 2026 at 18:15

Affected Product

Vendor OpenSC

Product OpenSC

Version < 0.27.0

Affected Versions OpenSC OpenSC < 0.27.0

CWE Classification

CWE-126

References

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    "published": "2026-03-30T17:03:55.914Z",
    "modified": "2026-04-01T18:15:33.347Z",
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