Ubuntu 23.04 USN-6125-1 Urgent: Snapd Access Vulnerability Warning

ubuntu

May 31, 2023

An intended access restriction in snapd could be bypassed by strict mode snaps.

Summary

An intended access restriction in snapd could be bypassed by strict mode snaps.

Software Description:

- snapd: Daemon and tooling that enable snap packages

Details:

It was discovered that the snap sandbox did not restrict the use of the

ioctl system call with a TIOCLINUX request. This could be exploited by a

malicious snap to inject commands into the controlling terminal which would

then be executed outside of the snap sandbox once the snap had exited. This

could allow an attacker to execute arbitrary commands outside of the

confined snap sandbox. Note: graphical terminal emulators like xterm,

gnome-terminal and others are not affected - this can only be exploited

when snaps are run on a virtual console.

Topics Covered

security advisory update critical Ubuntu command injection access restriction snapd

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.04:
  snapd                           2.59.1+23.04ubuntu1.1

Ubuntu 22.10:
  snapd                           2.58+22.10.1

Ubuntu 22.04 LTS:
  snapd                           2.58+22.04.1

Ubuntu 20.04 LTS:
  snapd                           2.58+20.04.1

Ubuntu 18.04 LTS:
  snapd                           2.58+18.04.1

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
  snapd                           2.54.3+16.04.0ubuntu0.1~esm6

In general, a standard system update will make all the necessary changes.