Denial of Service in urllib3 by Python Software Foundation
CVE-2021-33503

7.5HIGH

Key Information:

Vendor
Python
Status
Urllib3
Vendor
CVE Published:
29 June 2021

Summary

A vulnerability exists in urllib3, which can lead to denial of service when a URL with multiple '@' characters is processed. This issue stems from catastrophic backtracking in the authority regular expression, causing excessive resource consumption. If a user submits a URL or is redirected to one that exploits this vulnerability, it may result in significant performance degradation or application crash. Users are advised to upgrade to the latest version to mitigate this risk.

References

https://lists.fedoraproject.org/archives/list/package-ann...
vendor-advisoryx_refsource_FEDORA
https://lists.fedoraproject.org/archives/list/package-ann...
vendor-advisoryx_refsource_FEDORA
https://security.gentoo.org/glsa/202107-36
vendor-advisoryx_refsource_GENTOO

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.