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)