Summary
Notation vulnerable to denial of service from high number of artifact signatures
Workarounds
User should use secure and trusted container registries.
Credits
The notation project would like to thank Adam Korczynski (@AdamKorcz) for responsibly disclosing the issue found during an security audit (facilitated by OSTIF and sponsored by CNCF) and Shiwei Zhang (@shizhMSFT) for root cause analysis.
Impact
An attacker who controls or compromises a registry can make the registry serve an infinite number of signatures for the artifact, causing a denial of service to the host machine running notation verify.
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2023-33957 has a CVSS score of 5.7 (Medium). The vector is network-reachable, low 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 (1.0.0-rc.6); 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 problem has been fixed in the release v1.0.0-rc.6. Users should upgrade their notation packages to v1.0.0-rc.6 or above.
Frequently Asked Questions
- What is CVE-2023-33957? CVE-2023-33957 is a medium-severity uncontrolled resource consumption vulnerability in github.com/notaryproject/notation (go), affecting versions < 1.0.0-rc.6. It is fixed in 1.0.0-rc.6. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2023-33957? CVE-2023-33957 has a CVSS score of 5.7 (Medium). 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 are affected by CVE-2023-33957? github.com/notaryproject/notation (go) versions < 1.0.0-rc.6 is affected.
- Is there a fix for CVE-2023-33957? Yes. CVE-2023-33957 is fixed in 1.0.0-rc.6. Upgrade to this version or later.
- Is CVE-2023-33957 exploitable, and should I be worried? Whether CVE-2023-33957 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-2023-33957 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-2023-33957? Upgrade
github.com/notaryproject/notationto 1.0.0-rc.6 or later.