CVE-2021-33503

A flaw was found in python-urllib3. When provided with a URL containing many @ characters in the authority component, the authority's regular expression exhibits catastrophic backtracking. This flaw causes a denial of service if a URL is passed as a parameter or redirected via an HTTP redirect. The highest threat from this vulnerability is to system availability.

• Red Hat OpenShift Container Platform (OCP) 4 delivers the python-urllib3 package which includes a vulnerable version of urllib3 module, however from OCP 4.6 the python-urllib3 package is no longer shipped. OCP 4.5 is out of support scope for Moderate and Low impact vulnerabilities, hence is marked Out Of Support Scope. The python-urllib3 package used in OCP 3.11 is not affected by this flaw.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.