GHSA-q2q7-5pp4-w6pg
Catastrophic backtracking in URL authority parser when passed URL containing many @ characters
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
When provided with a URL containing many `@` characters in the authority component the authority regular expression exhibits catastrophic backtracking causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.
### Patches
The issue has been fixed in urllib3 v1.26.5.
### References
- [CVE-2021-33503](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-33503)
- [JVNVU#92413403 (English)](https://jvn.jp/en/vu/JVNVU92413403/)
- [JVNVU#92413403 (Japanese)](https://jvn.jp/vu/JVNVU92413403/)
- [urllib3 v1.26.5](https://github.com/urllib3/urllib3/releases/tag/1.26.5)
### For more information
If you have any questions or comments about this advisory:
* Ask in our [community Discord](https://discord.gg/urllib3)
* Email [[email protected]](mailto:[email protected])
References
External links from the advisory. They lead to third-party sites.
- https://github.com/urllib3/urllib3/security/advisories/GHSA-q2q7-5pp4-w6pg
- https://nvd.nist.gov/vuln/detail/CVE-2021-33503
- https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec
- https://github.com/urllib3/urllib3/commit/5b047b645f5f93900d5e2fc31230848c25eb1f5f#diff-52026d639119bf1e0364836b4e8a18bd9ed3c95c6ba39b26534a…
- https://github.com/advisories/GHSA-q2q7-5pp4-w6pg
- https://github.com/pypa/advisory-database/tree/main/vulns/urllib3/PYSEC-2021-108.yaml
- https://github.com/urllib3/urllib3
- https://lists.fedoraproject.org/archives/list/[email protected]/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W
- https://lists.fedoraproject.org/archives/list/[email protected]/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73
- https://security.gentoo.org/glsa/202107-36
- https://www.oracle.com/security-alerts/cpuoct2021.html