Directory traversal vulnerability in the containsdotdot function in src/names.c in GNU tar allows user-assisted remote attackers to overwrite arbitrary files via certain //.. (slash slash dot dot) sequences in directory symlinks in a TAR archive.
A heap-based buffer overflow flaw was found in the way tar and cpio archive manipulation tools expanded archives with certain character in the archive name. If a local user was tricked into expanding a specially-crafted archive, it could cause the tar, cpio executables to crash or, potentially, to execute arbitrary code with the privileges of the user running the utility.
Link to advisory: [1] http://www.agrs.tu-berlin.de/index.php?id=78327
Acknowledgements:
Red Hat would like to thank Jakob Lell for responsibly reporting this issue.