GNU cpio through 2.13 allows attackers to execute arbitrary code via a crafted pattern file, because of a dstring.c dsfgetstr integer overflow that triggers an out-of-bounds heap write. NOTE: it is unclear whether there are common cases where the pattern file, associated with the -E option, is untrusted data.

GNU cpio could allow a local authenticated attacker to gain elevated privileges on the system, caused by the failure to properly validate input files when generating TAR archives. An attacker could exploit this vulnerability to inject any tar content and compromise the system.

cpio, as used in build 2007.05.10, 2010.07.28, and possibly other versions, allows remote attackers to overwrite arbitrary files via a symlink within an RPM package 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.

The cpiosafernamesuffix function in util.c in cpio 2.11 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted cpio file.

A path traversal vulnerability was found in the CPIO utility. This issue could allow a remote unauthenticated attacker to trick a user into opening a specially crafted archive. During the extraction process, the archiver could follow symlinks outside of the intended directory, which allows files to be written in arbitrary directories through symlinks.

Heap-based buffer overflow in the processcopyin function in GNU Cpio 2.11 allows remote attackers to cause a denial of service via a large block value in a cpio archive.

Race condition in cpio 2.6 and earlier allows local users to modify permissions of arbitrary files via a hard link attack on a file while it is being decompressed, whose permissions are changed by cpio after the decompression is complete.

GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed.

GNU cpio is vulnerable to an uncontrolled memory allocation in the makepath function at src/makepath.c. The function uses alloca to allocate stack memory based on the length of argpath, which is derived from an archive-controlled pathname during extraction. A malicious cpio archive containing a sufficiently long nested pathname causes an unbounded stack allocation, resulting in a stack overflow and crash of the cpio process. An attacker who can supply a crafted cpio archive to a victim who extracts it can cause a denial of service.

GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the linktoname function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files.

Directory traversal vulnerability in cpio 2.6 and earlier allows remote attackers to write to arbitrary directories via a .. (dot dot) in a cpio file.

Buffer overflow in cpio 2.6-8.FC4 on 64-bit platforms, when creating a cpio archive, allows local users to cause a denial of service (crash) and possibly execute arbitrary code via a file whose size is represented by more than 8 digits.

cpio 2.11, when using the --no-absolute-filenames option, allows local users to write to arbitrary files via a symlink attack on a file in an archive.

Common Vulnerabilities and Exposures assigned an identifier CVE-2007-4476 to the following vulnerability:

Bug in the safernamesuffix function in GNU tar may lead to a "crashing stack". It can be used to crash tar while extracting archive containing file with long name containing unsafe prefix.

Affected function is also part of cpio source code.

References:

http://www.novell.com/linux/security/advisories/200718sr.html http://lists.gnu.org/archive/html/bug-cpio/2007-08/msg00002.html