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Vulnerability of glibc: unreachable memory reading via fnmatch

Synthesis of the vulnerability 

An attacker can force a read at an invalid address in fnmatch() of the glibc, in order to trigger a denial of service.
Impacted products: Arkoon FAST360, BIG-IP Hardware, TMOS, Ubuntu, Unix (platform) ~ not comprehensive.
Severity of this bulletin: 1/4.
Creation date: 26/02/2015.
Références of this threat: 18032, CVE-2015-8984, K29241247, STORM-2015-09-EN, STORM-2015-10-EN, STORM-2015-11-EN.2, STORM-2015-12-EN, USN-3239-1, USN-3239-2, USN-3239-3, VIGILANCE-VUL-16275.

Description of the vulnerability 

The fnmatch() function of the glibc checks if a string matches a pattern:
  fnmatch(pattern, string, flags);
For example:
  if (fnmatch("*.txt", "file.txt", 0)) ...

However, if the pattern contains an unclosed '[', the internal_fnmatch() function tries to read a memory area which is not reachable, which triggers a fatal error.

An attacker can therefore force a read at an invalid address in fnmatch() of the glibc, in order to trigger a denial of service.
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This cybersecurity announce impacts software or systems such as Arkoon FAST360, BIG-IP Hardware, TMOS, Ubuntu, Unix (platform) ~ not comprehensive.

Our Vigil@nce team determined that the severity of this threat alert is low.

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 specialist ability can exploit this computer weakness alert.

Solutions for this threat 

glibc: patch for fnmatch.
A patch is available in information sources.

Arkoon Fast360: version 5.0/35.
The version 5.0/35 is fixed.

Arkoon Fast360: version 6.0/9.
The version 6.0/9 is fixed.

F5 BIG-IP: solution for glibc CVE-2015-8984.
The solution is indicated in information sources.

Ubuntu: new libc6 packages.
New packages are available:
  Ubuntu 16.04 LTS: libc6 2.23-0ubuntu7
  Ubuntu 14.04 LTS: libc6 2.19-0ubuntu6.11
  Ubuntu 12.04 LTS: libc6 2.15-0ubuntu10.18
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