CVE Vulnerabilities

CVE-2021-28363

Improper Certificate Validation

Published: Mar 15, 2021 | Modified: Nov 07, 2023
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS 2.x
6.4 MEDIUM
AV:N/AC:L/Au:N/C:P/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

The urllib3 library 1.26.x before 1.26.4 for Python omits SSL certificate validation in some cases involving HTTPS to HTTPS proxies. The initial connection to the HTTPS proxy (if an SSLContext isnt given via proxy_config) doesnt verify the hostname of the certificate. This means certificates for different servers that still validate properly with the default urllib3 SSLContext will be silently accepted.

Weakness

The product does not validate, or incorrectly validates, a certificate.

Affected Software

Name Vendor Start Version End Version
Urllib3 Python 1.26.0 *

Potential Mitigations

References