HMAC validation bypass via uninitialized output length
Published Oct 1, 2024 · Updated Aug 25, 2026
Use of an uninitialized variable in golang-fips/openssl 2.0.3 and earlier allows local users to receive incorrect HMAC output. _goboringcrypto_HMAC_Final passes a non-null buffer to EVP_DigestSignFinal without initializing the required output-length argument. FIPS mode and an affected Go build are required; a stack-dependent failure can accept a zero HMAC or produce an all-zero derived key.
Summary
What happened
Use of an uninitialized variable in golang-fips/openssl 2.0.3 and earlier allows local users to receive incorrect HMAC output. _goboringcrypto_HMAC_Final passes a non-null buffer to EVP_DigestSignFinal without initializing the required output-length argument. FIPS mode and an affected Go build are required; a stack-dependent failure can accept a zero HMAC or produce an all-zero derived key.
The record
- CVE
- CVE-2024-9355
- Published
- Oct 1, 2024
- Updated
- Aug 25, 2026
- Vendor
- Red Hat
- Product
- Red Hat OpenShift Virtualization
- Classifications
- CWE-457
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 1, 2024CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo