1. Ubuntu Security Notices
  2. USN-6125-1

USN-6125-1: snapd vulnerability

Publication date

31 May 2023

Overview

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

Releases

Packages

  • 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.

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.

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
23.04 lunar snapd –  2.59.1+23.04ubuntu1.1
22.10 kinetic snapd –  2.58+22.10.1
22.04 jammy snapd –  2.58+22.04.1
20.04 focal snapd –  2.58+20.04.1
18.04 bionic snapd –  2.58+18.04.1
16.04 xenial snapd –  2.54.3+16.04.0ubuntu0.1~esm6  

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References

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