Summary
Fiona affected by CVE-2023-45853 related to MiniZip madler-zlib
Vulnerability scan of fiona shows CVE-2023-45853. The vulnerability is in GDAL, a dependency of fiona.
Details
Fiona depends on GDAL and GDAL has a port of minizip. MiniZip in zlib through 1.3 has an integer overflow and resultant heap-based buffer overflow in zipOpenNewFileInZip4_64 via a long filename, comment, or extra field. The GDAL project has addressed the CVE in version 3.8.0. See https://lists.osgeo.org/pipermail/gdal-dev/2023-November/057881.html.
The Fiona version 1.9.6 wheels on PyPI include GDAL version 3.6.4 and thus could be vulnerable. All of the Fiona 1.10 pre-release wheels in PyPI include GDAL version 3.8.4 and are not vulnerable.
Impact
Systems which use GDAL versions prior to 3.8.0 to open unchecked zip files, whether in combination with fiona or not, could be susceptible to buffer overflows.
An arithmetic operation produces a value that exceeds the integer type's maximum, causing it to wrap to an unexpected small value. Typical impact: incorrect size calculations leading to heap overflows or logic errors.
GHSA-Q5FM-55C2-V6J9 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 (1.10b1); 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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Frequently Asked Questions
- What is GHSA-Q5FM-55C2-V6J9? GHSA-Q5FM-55C2-V6J9 is a critical-severity integer overflow or wraparound vulnerability in fiona (pip), affecting versions < 1.10b1. It is fixed in 1.10b1. An arithmetic operation produces a value that exceeds the integer type's maximum, causing it to wrap to an unexpected small value.
- How severe is GHSA-Q5FM-55C2-V6J9? GHSA-Q5FM-55C2-V6J9 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 fiona are affected by GHSA-Q5FM-55C2-V6J9? fiona (pip) versions < 1.10b1 is affected.
- Is there a fix for GHSA-Q5FM-55C2-V6J9? Yes. GHSA-Q5FM-55C2-V6J9 is fixed in 1.10b1. Upgrade to this version or later.
- Is GHSA-Q5FM-55C2-V6J9 exploitable, and should I be worried? Whether GHSA-Q5FM-55C2-V6J9 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 GHSA-Q5FM-55C2-V6J9 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 GHSA-Q5FM-55C2-V6J9? Upgrade
fionato 1.10b1 or later.