==========================================================================
Ubuntu Security Notice USN-4692-1
January 13, 2021

tar vulnerabilities
==========================================================================

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM
- Ubuntu 12.04 ESM

Summary:

Several security issues were fixed in tar.

Software Description:
- tar: GNU version of the tar archiving utility

Details:

Chris Siebenmann discovered that tar incorrectly handled extracting files
resized during extraction when invoked with the --sparse flag. An attacker
could possibly use this issue to cause a denial of service. This issue
only affected Ubuntu 12.04 ESM, Ubuntu 14.04 ESM, Ubuntu 16.04 LTS and
Ubuntu 18.04 LTS. (CVE-2018-20482)

Daniel Axtens discovered that tar incorrectly handled certain malformed
tar files. If a user or automated system were tricked into processing a
specially crafted tar archive, a remote attacker could use this issue to
cause tar to crash, resulting in a denial of service. (CVE-2019-9923)

Update instructions:

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

Ubuntu 20.10:
  tar                             1.30+dfsg-7ubuntu0.20.10.1

Ubuntu 20.04 LTS:
  tar                             1.30+dfsg-7ubuntu0.20.04.1

Ubuntu 18.04 LTS:
  tar                             1.29b-2ubuntu0.2

Ubuntu 16.04 LTS:
  tar                             1.28-2.1ubuntu0.2

Ubuntu 14.04 ESM:
  tar                             1.27.1-1ubuntu0.1+esm1

Ubuntu 12.04 ESM:
  tar                             1.26-4ubuntu1.2

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

References:
  https://usn.ubuntu.com/4692-1
  CVE-2018-20482, CVE-2019-9923

Package Information:
  https://launchpad.net/ubuntu/+source/tar/1.30+dfsg-7ubuntu0.20.10.1
  https://launchpad.net/ubuntu/+source/tar/1.30+dfsg-7ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/tar/1.29b-2ubuntu0.2
  https://launchpad.net/ubuntu/+source/tar/1.28-2.1ubuntu0.2