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

What is CVE-2021-33503?

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.