Polkit Security Vulnerability CVE-2021-4034¶

Overview¶

On Tuesday 25th January 2022, a local privilege escalation was discovered in the polkit component in all major Linux distributions. This toolkit is responsible for organising/controlling how non-privileged processes communicate with privileged ones. A vulnerability was discovered in the pbexec command in which a specifically crafted environment variable can be leveraged to execute arbitrary code, leading to a local privilege escalation.

• Red Hat

• Ubuntu

• AlmaLinux

UKFast’s Response¶

Once patches are available, UKFast is encouraging all clients to upgrade polkit to the latest version, applying the appropriate mitigations where upgrade isn’t an option. For our part, UKFast is currently working through all our systems to be absolutely sure we are protected.

Our support teams are looking at not only updating those products and services managed by UKFast, but are also looking into the wider scope of affected applications, with a view to better informing our clients the best mitigation methods with systems they manage.

Identification¶

Manual Mitigation¶

In lieu of a patched version of polkit, Red Hat have detailed an alternative method of mitigation, linked below.

• Red Hat