Description
osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.12, A stack buffer overflow vulnerability exists in osslsigncode in several signature verification paths. During verification of a PKCS#7 signature, the code copies the digest value from a parsed SpcIndirectDataContent structure into a fixed-size stack buffer (mdbuf[EVP_MAX_MD_SIZE], 64 bytes) without validating that the source length fits within the destination buffer. This pattern is present in the verification handlers for PE, MSI, CAB, and script files. An attacker can craft a malicious signed file with an oversized digest field in SpcIndirectDataContent. When a user verifies such a file with osslsigncode verify, the unbounded memcpy can overflow the stack buffer and corrupt adjacent stack state. This vulnerability is fixed in 2.12.
Affected products
osslsigncode_project: osslsigncode
References3
- github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-… Vendor Advisory
- github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd84… Patch
- github.com/mtrojnar/osslsigncode/releases/tag/2.12 ProductRelease Notes
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 6 · as of 12 November 2026
- CWE
- CWE-121CWE-787
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