GHSA-9r4w-jg96-92mv
MEDIUMGHSA-9r4w-jg96-92mv is a medium-severity (CVSS 6.8) CWE-1285 vulnerability in github.com/google/go-attestation. O3 Security confirms whether GHSA-9r4w-jg96-92mv is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Go-Attestation: Hash injection into trusted measurement list via unskipped SignatureHeaderSize vendor bytes in parseEfiSignatureList()
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/google/go-attestationReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
parseEfiSignatureList() in attest/internal/events.go does not skip SignatureHeaderSize vendor bytes before reading EFI_SIGNATURE_LIST signature entries, violating UEFI specification section 31.4.1.
Impact
For hashSHA256SigGUID lists, attacker-controlled vendor header bytes are appended directly to the trusted SHA256 hash list. A crafted TPM event log can inject arbitrary SHA256 hashes into the verifier's trusted measurement database, allowing a remote attestation verifier to accept a compromised boot state as legitimate — breaking the core integrity guarantee of remote attestation.
Root Cause
After binary.Read(&signatures.Header) reads 28 bytes, buf points to the start of the SignatureHeaderSize vendor bytes. Both entry loops start at sigOffset := 0 instead of sigOffset := SignatureHeaderSize, causing vendor bytes to be read as signature entries.
Affected versions
All versions through commit f877374 (2026-05-15).
Fix
Pull request: https://github.com/google/go-attestation/pull/502
- Add bound check:
SignatureHeaderSizemust not exceed remaining list space - Skip
SignatureHeaderSizebytes before both entry loops - Regression test:
TestParseEfiSignatureListNonZeroSignatureHeaderSize
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/google/go-attestation | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/google/go-attestation. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of github.com/google/go-attestation has shipped for GHSA-9r4w-jg96-92mv yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-9r4w-jg96-92mv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-9r4w-jg96-92mv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9r4w-jg96-92mv in your dependencies?
O3 detects GHSA-9r4w-jg96-92mv across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.