Summary
Potential DoS with NumberFilter conversion to integer values.
Workarounds
Users may manually apply an equivalent validator if they are not able to upgrade.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the django-filter repo
Thanks to Marcin Waraksa for the report.
Impact
Automatically generated NumberFilter instances, whose value was later converted to an integer, were subject to potential DoS from maliciously input using exponential format with sufficiently large exponents.
CVE-2020-15225 has a CVSS score of 7.5 (High). 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 (2.4.0); 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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Version 2.4.0+ applies a MaxValueValidator with a a default limit_value of 1e50 to the form field used by NumberFilter instances.
In addition, NumberFilter implements the new get_max_validator() which should return a configured validator instance to customise the limit, or else None to disable the additional validation.
Frequently Asked Questions
- What is CVE-2020-15225? CVE-2020-15225 is a high-severity security vulnerability in django-filter (pip), affecting versions < 2.4.0. It is fixed in 2.4.0.
- How severe is CVE-2020-15225? CVE-2020-15225 has a CVSS score of 7.5 (High). 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 django-filter are affected by CVE-2020-15225? django-filter (pip) versions < 2.4.0 is affected.
- Is there a fix for CVE-2020-15225? Yes. CVE-2020-15225 is fixed in 2.4.0. Upgrade to this version or later.
- Is CVE-2020-15225 exploitable, and should I be worried? Whether CVE-2020-15225 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-2020-15225 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-2020-15225? Upgrade
django-filterto 2.4.0 or later.