Arch Linux Security Advisory ASA-202204-2
========================================
Severity: High
Date    : 2022-04-04
CVE-ID  : CVE-2021-4034 CVE-2021-4115
Package : polkit
Type    : multiple issues
Remote  : No
Link    : https://security.archlinux.org/AVG-2654

Summary
======
The package polkit before version 0.120-5 is vulnerable to multiple
issues including privilege escalation and denial of service.

Resolution
=========
Upgrade to 0.120-5.

# pacman -Syu "polkit>=0.120-5"

The problems have been fixed upstream but no release is available yet.

Workaround
=========
None.

Description
==========
- CVE-2021-4034 (privilege escalation)

A local privilege escalation vulnerability was found on polkit's pkexec
utility. The pkexec application is a setuid tool designed to allow
unprivileged users to run commands as privileged users according
predefined policies. The current version of pkexec doesn't handle the
calling parameters count correctly and ends trying to execute
environment variables as commands. An attacker can leverage this by
crafting environment variables in such a way it'll induce pkexec to
execute arbitrary code. When successfully executed the attack can cause
a local privilege escalation given unprivileged users administrative
rights on the target machine.

- CVE-2021-4115 (denial of service)

There is a file descriptor leak in polkit, which can enable an
unprivileged user to cause polkit to crash, due to file descriptor
exhaustion.

Impact
=====
A local attacker is able to crash the process or elevate privileges on
the affected host.

References
=========
https://access.redhat.com/security/cve/CVE-2021-4034
https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
https://www.openwall.com/lists/oss-security/2022/02/18/5
https://gitlab.freedesktop.org/polkit/polkit/-/issues/141
https://gitlab.freedesktop.org/polkit/polkit/-/commit/41cb093f554da8772362654a128a84dd8a5542a7
https://security.archlinux.org/CVE-2021-4034
https://security.archlinux.org/CVE-2021-4115