The GNU tar program saves many files together in one archive and can restore individual files (or all of the files) from that archive.
Jim Meyering discovered a buffer overflow bug in the way GNU tar extracts malformed archives. By tricking a user into extracting a malicious tar archive, it is possible to execute arbitrary code as the user running tar. The Common Vulnerabilities and Exposures project (cve.mitre.org) assigned the name CVE-2006-0300 to this issue.
Users of tar should upgrade to this updated package, which contains a backported patch to correct this issue.