Summary
Potential buffer overflow in psd-tools
Workarounds
Without Cython present on installation, buffer overflow does not occur but IndexError will be thrown. However, already installed psd-tools with Cython extention should be upgraded.
References
https://github.com/psd-tools/psd-tools/pull/198
For more information
If you have any questions or comments about this advisory:
- Open an issue in psd-tools
Impact
An issue was discovered in psd-tools before 1.9.4. The Cython implementation of RLE decoding did not check for malformed PSD input data during decoding to the PIL.Image or NumPy format, leading to a Buffer Overflow.
CVE-2020-10571 has a CVSS score of 9.8 (Critical). The vector is network-reachable, no privileges required, and no user interaction. 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 (1.9.4); 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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See it in your environmentNew to Kodem? Get a demo →Remediation advice
Users of psd-tools version v1.8.37 to v1.9.3 should upgrade to v1.9.4.
Frequently Asked Questions
- What is CVE-2020-10571? CVE-2020-10571 is a critical-severity security vulnerability in psd-tools (pip), affecting versions >= 1.8.37, < 1.9.3. It is fixed in 1.9.4.
- How severe is CVE-2020-10571? CVE-2020-10571 has a CVSS score of 9.8 (Critical). 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 psd-tools are affected by CVE-2020-10571? psd-tools (pip) versions >= 1.8.37, < 1.9.3 is affected.
- Is there a fix for CVE-2020-10571? Yes. CVE-2020-10571 is fixed in 1.9.4. Upgrade to this version or later.
- Is CVE-2020-10571 exploitable, and should I be worried? Whether CVE-2020-10571 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-2020-10571 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-2020-10571? Upgrade
psd-toolsto 1.9.4 or later.