Pavel Cahyna

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

**Name of the Vulnerable Software and Affected Versions** FreeBSD versions 4.11 through 6.1 NetBSD versions 2.0 through 4.0 beta before 20060823 OpenBSD versions 3.8 and 3.9 before 20060902 **Description** A buffer overflow issue exists in the sppp driver, allowing remote attackers to cause a denial of service, obtain sensitive information, and possibly execute arbitrary code via crafted Link Control Protocol packets. The overflow occurs when an option length exceeds the overall length in packets, affecting pppoe and ippp. **Recommendations** For FreeBSD versions 4.11 through 6.1, update to a version outside of this range to resolve the issue. For NetBSD versions 2.0 through 4.0 beta before 20060823, update to a version after 20060823 to resolve the issue. For OpenBSD versions 3.8 and 3.9 before 20060902, update to a version after 20060902 to resolve the issue.