Package manager snapd by Canonical contains vulnerability dubbed Dirty Cow (CVE-2019-7304), which can be exploited by an attacker to gain root access on Linux systems. It doesn't allow hackers to break into vulnerable machines remotely, but once attackers have a foothold on any unpatched system they can turn a simple intrusion into a bad hack where they have control over the entire OS. Proof of concept code is available. The vulnerability affects all Linux systems with snapd installed, especially Ubuntu which comes with snapd preinstalled. Snapd version 2.37.1 was released to address the issue.