A Snapcraft security update has been released for Ubuntu Linux 16.04 LTS and 18.04 LTS.

USN-4661-1: Snapcraft vulnerability

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Ubuntu Security Notice USN-4661-1
December 03, 2020

snapcraft vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

An intended access restriction could be bypassed in snaps built with
Snapcraft

Software Description:
- snapcraft: easily craft snaps

Details:

It was discovered that Snapcraft includes the current directory when
configuring LD_LIBRARY_PATH for application commands. If a user were
tricked into installing a malicious snap or downloading a malicious
library, under certain circumstances an attacker could exploit this to
affect strict mode snaps that have access to the library and when
launched from the directory containing the library.

Update instructions:

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

Ubuntu 18.04 LTS:
snapcraft 2.43.1+18.04.1

Ubuntu 16.04 LTS:
snapcraft 2.43.1+16.04.1

For users of the snap package, Snapcraft will automatically refresh
itself to Snapcraft 4.4.4 which is unaffected. For users of the deb
package, on Ubuntu 16.04 LTS and 18.04 LTS, please perform a standard
system update. In either case, once Snapcraft has been updated, you need
to rebuild any packages built with the affected Snapcraft.

References:
  https://usn.ubuntu.com/4661-1
CVE-2020-27348,   https://launchpad.net/bugs/1901572

Package Information:
  https://launchpad.net/ubuntu/+source/snapcraft/2.43.1+18.04.1
  https://launchpad.net/ubuntu/+source/snapcraft/2.43.1+16.04.1