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Vulnerability of GNU patch: directory traversal via symlink 2

Synthesis of the vulnerability 

An attacker can transmit to the victim a malicious diff file, to traverse directories of patch, in order to create a file outside the current directory.
Vulnerable products: Fedora, Ubuntu, Unix (platform) ~ not comprehensive.
Severity of this weakness: 2/4.
Creation date: 26/01/2015.
Références of this bulletin: 775901, CVE-2015-1396, FEDORA-2015-1553, FEDORA-2015-3556, USN-2651-1, VIGILANCE-VUL-16050.

Description of the vulnerability 

The patch program supports patches created in Git format. The "new file mode" syntax indicates the mode of the file to create.

However, by using a symlink mode, the patch command accepts to escape from the current directory, because all cases of VIGILANCE-VUL-15968 were not fixed.

An attacker can therefore transmit to the victim a malicious diff file, to traverse directories of patch, in order to create a file outside the current directory.
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This computer vulnerability announce impacts software or systems such as Fedora, Ubuntu, Unix (platform) ~ not comprehensive.

Our Vigil@nce team determined that the severity of this cybersecurity bulletin is medium.

The trust level is of type confirmed by the editor, with an origin of document.

A proof of concept or an attack tool is available, so your teams have to process this alert. An attacker with a technician ability can exploit this threat alert.

Solutions for this threat 

GNU patch: version 2.7.3.
The version 2.7.3 is fixed:
  ftp://ftp.gnu.org/gnu/patch

GNU patch: patch for symlink 2.
A patch is available in information sources.

Fedora 21: new patch packages.
New packages are available:
  Fedora 21: patch 2.7.5-1.fc21

Ubuntu: new patch packages.
New packages are available:
  Ubuntu 14.10: patch 2.7.1-5ubuntu0.3
  Ubuntu 14.04 LTS: patch 2.7.1-4ubuntu2.3
  Ubuntu 12.04 LTS: patch 2.6.1-3ubuntu0.1
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