Gentoo update for urllib3

Published: 2021-07-15

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-28363 CVE-2021-33503
CWE-ID	CWE-297 CWE-400
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Gentoo Linux Operating systems & Components / Operating system
Vendor	Gentoo

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper validation of certificate with host mismatch

EUVDB-ID: #VU51604

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-28363

CWE-ID: CWE-297 - Improper Validation of Certificate with Host Mismatch

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to urllib3 library 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. A remote attacker can supply a valid SSL certificate for a different hostname and perform Man-in-the-Middle (MitM) attack.

Mitigation

Update the affected packages.
dev-python/urllib3 to version: 1.26.5

Vulnerable software versions

Gentoo Linux: All versions

External links

http://security.gentoo.org/
http://security.gentoo.org/glsa/202107-36

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Resource exhaustion

EUVDB-ID: #VU54077