CVE-2021-3626 Windows version of Multipass unauthenticated localhost tcp control socket can perform mounts

High 8.8 Published 1 Oct 2021 Updated 17 Sep 2024

Local attackers can exploit an unauthenticated TCP control socket in Multipass on Windows to mount host directories into guests, leading to privilege escalation.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-3626?

CVE-2021-3626 is a high-severity missing authorization vulnerability in Canonical Multipass, published on 1 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

The Windows version of Multipass before 1.7.0 allowed any local process to connect to the localhost TCP control socket to perform mounts from the operating system to a guest, allowing for privilege escalation.

Weakness: CWE-73, CWE-284

Which versions are affected by CVE-2021-3626?

It affects 1 product.

Products include Canonical Multipass.

How do I fix CVE-2021-3626?

No fix has been published for CVE-2021-3626 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2021-3626 being exploited?

There is no known exploitation of CVE-2021-3626 in the wild and no public exploit code.

Sources

Also known as GHSA-68wj-3pj9-r3hp.