Vulnerability Note VU#967332

GNU C Library (glibc) __nss_hostname_digits_dots() function vulnerable to buffer overflow

Original Release date: 28 Jan 2015 | Last revised: 22 Oct 2015


The __nss_hostname_digits_dots() function of the GNU C Library (glibc) allows a buffer overflow condition in which arbitrary code may be executed. This vulnerability has been assigned CVE-2015-0235, and is referred to in the media by the name "GHOST".


According to Qualys, the vulnerability is "a buffer overflow in the __nss_hostname_digits_dots() function of the GNU C Library (glibc). This bug is reachable both locally and remotely via the gethostbyname*() functions" and furthermore, "arbitrary code execution can be achieved" by use of the buffer overflow.

All versions of glibc from glibc-2.2 (released 2010-11-10) until glibc-2.17 are vulnerable. The vulnerability was patched on 2013-05-21, prior to the release of glibc-2.18.

For more details, please see the full Qualys Security Advisory.


The __nss_hostname_digits_dots() function allows a buffer overflow condition in which arbitrary code may be executed. The impact may vary depending on if the use case is local or remote.


Apply an update

Affected users may apply a patch or update to glibc-2.18 or later. The Vendor Status information below provides more information on updates.

Vendor Information (Learn More)

Some older, no longer supported versions of linux distributions may contain an older version of glibc that is vulnerable. Please check with your vendor to find out if you need to upgrade to a newer operating system in order to address this issue.

VendorStatusDate NotifiedDate Updated
Arch LinuxAffected28 Jan 201530 Jan 2015
Blue Coat SystemsAffected-30 Jan 2015
Cisco Systems, Inc.Affected-30 Jan 2015
CitrixAffected-30 Jan 2015
Debian GNU/LinuxAffected28 Jan 201528 Jan 2015
F5 Networks, Inc.Affected-30 Jan 2015
Gentoo LinuxAffected28 Jan 201530 Jan 2015
Juniper Networks, Inc.Affected-30 Jan 2015
NEC CorporationAffected-22 Oct 2015
NetAppAffected-30 Jan 2015
openSUSE projectAffected28 Jan 201530 Jan 2015
Openwall GNU/*/LinuxAffected28 Jan 201530 Jan 2015
Red Hat, Inc.Affected28 Jan 201530 Jan 2015
Slackware Linux Inc.Affected28 Jan 201528 Jan 2015
SUSE LinuxAffected28 Jan 201528 Jan 2015
If you are a vendor and your product is affected, let us know.View More »

CVSS Metrics (Learn More)

Group Score Vector
Base 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C
Temporal 7.8 E:POC/RL:OF/RC:C
Environmental 5.9 CDP:ND/TD:M/CR:ND/IR:ND/AR:ND



Credit to Qualys for discovering the vulnerability.

This document was written by Garret Wassermann.

Other Information

  • CVE IDs: CVE-2015-0235
  • Date Public: 28 Jan 2015
  • Date First Published: 28 Jan 2015
  • Date Last Updated: 22 Oct 2015
  • Document Revision: 24


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