Ubuntu Security Notice USN-4692-1

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


Several security issues were fixed in tar.

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


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.

CVE-2018-20482, CVE-2019-9923

Package Information: