Summary
notation-go has an OS error when setting CRL cache leads to denial of signature verification
The issue was identified during Quarkslab's security audit on the Certificate Revocation List (CRL) based revocation check feature.
After retrieving the CRL, notation-go attempts to update the CRL cache using the os.Rename method. However, this operation may fail due to operating system-specific limitations, particularly when the source and destination paths are on different mount points. This failure could lead to an unexpected program termination.
Details
In method crl.(*FileCache).Set, a temporary file is created in the OS dedicated area (like /tmp for, usually, Linux/Unix). The file is written and then it is tried to move it to the dedicated notation cache directory thanks os.Rename. As specified in Go documentation, OS specific restriction may apply. When used with Linux OS, it is relying on rename syscall from the libc and as per the documentation, moving a file to a different mountpoint raises an EXDEV error, interpreted as Cross device link not permitted error.
Some Linux distribution, like RedHat use a dedicated filesystem (tmpfs), mounted on a specific mountpoint (usually /tmp) for temporary files. When using such OS, revocation check based on CRL will repeatedly crash notation.
PoC
- Ensure that the temporary file storage area (e.g., /tmp) is mounted on a different mount point than the user's 'notation' cache directory.
- Either disable the Online Certificate Status Protocol (OCSP) revocation check, or utilize certificates that exclusively support Certificate Revocation Lists (CRLs) for revocation check.
- Try to verify a previously generated signature using the 'notation' tool.
Impact
The signature verification process is aborted as process crashes.
CVE-2024-51491 has a CVSS score of 3.3 (Low). The vector is requires local access, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.3.0-rc.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The cache file should be created, written, then copied to the wanted final location, and finally removed. Additionally, this error shouldn't lead to a crash as it is not fatal and shouldn't prevent the rest of the program to properly continue
Frequently Asked Questions
- What is CVE-2024-51491? CVE-2024-51491 is a low-severity security vulnerability in github.com/notaryproject/notation-go (go), affecting versions = 1.3.0-rc.1. It is fixed in 1.3.0-rc.2.
- How severe is CVE-2024-51491? CVE-2024-51491 has a CVSS score of 3.3 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/notaryproject/notation-go are affected by CVE-2024-51491? github.com/notaryproject/notation-go (go) versions = 1.3.0-rc.1 is affected.
- Is there a fix for CVE-2024-51491? Yes. CVE-2024-51491 is fixed in 1.3.0-rc.2. Upgrade to this version or later.
- Is CVE-2024-51491 exploitable, and should I be worried? Whether CVE-2024-51491 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2024-51491 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2024-51491? Upgrade
github.com/notaryproject/notation-goto 1.3.0-rc.2 or later.