CVE-2021-28363

2021-03-1500:00:00

ubuntu.com

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

6.4 Medium

CVSS2

Access Vector

NETWORK

Access Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:L/Au:N/C:P/I:P/A:N

0.001 Low

EPSS

Percentile

48.5%

JSON

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 isn’t given via
proxy_config) doesn’t 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.

Notes

Author	Note
mdeslaur	the python-pip package bundles python-urllib3 binaries when built. After updating python-urllib3, a no-change rebuild of python-pip is required.
avital	introduced in 1.26.0