Ghost vulnerability

Red Hat Product Security has been made aware of a critical vulnerability in the glibc library, which has been assigned CVE-2015-0235 and is commonly referred to as 'GHOST'. All versions of glibc shipped with all variants of Red Hat Enterprise Linux are affected.

Background

GHOST is a 'buffer overflow' bug affecting the gethostbyname() and gethostbyname2() function calls in the glibc library. This vulnerability allows a remote attacker that is able to make an application call to either of these functions to execute arbitrary code with the permissions of the user running the application.

Exploitation

The gethostbyname() function calls are used for DNS resolving, which is a very common event. To exploit this vulnerability, an attacker must trigger a buffer overflow by supplying an invalid hostname argument to an application that performs a DNS resolution.

Additional Information

• Red Hat Enterprise Linux: Application Compatibility GUIDE
• Is compat-glibc affected by GHOST, glibc vulnerability (CVE-2015-0235)?
• Why does customized locale info disappear after updating glibc-* (CVE-2015-0235)?
• Are RHEV-H images affected by GHOST (CVE-2015-0235)?

All versions of glibc shipped with all variants of Red Hat Enterprise Linux are affected.

• Red Hat Enterprise Linux Server 5
• Red Hat Enterprise Linux Server (v. 6)
• Red Hat Enterprise Linux Server (v. 7)
• Red Hat Enterprise Linux Desktop 5
• Red Hat Enterprise Linux Desktop 6
• Red Hat Enterprise Linux Desktop 7
• Red Hat Enterprise Linux HPC Node 6
• Red Hat Enterprise Linux HPC Node 7
• Red Hat Enterprise Linux Workstation 6
• Red Hat Enterprise Linux Workstation 7
• Red Hat Enterprise Linux Server EUS (v. 6.6)
• Red Hat Enterprise Linux Server EUS (v. 6.5)
• Red Hat Enterprise Linux Server EUS (v. 6.4)
• Red Hat Enterprise Linux Server EUS (v. 5.9)
• Red Hat Enterprise Linux ELS (v. 4)*

*An active ELS subscription is required for access to this patch in RHEL 4. Please contact Red Hat sales or your specific sales representative for more information if your account does not have an active ELS subscription.

What is the Red Hat Enterprise Linux Extended Life Cycle Support Add-On (ELS)?

As a Red Hat customer, the easiest way to check for the vulnerability or confirm remediation is the Red Hat Access Lab: GHOST - gethostbyname Detector. Please make sure that you have installed the correct version prior and if you are downloading the package for RHEL 4, you must be subscribed to the ELS channel or have downloaded the ELS version of the package. The RHEL 4 non-ELS subscription version will cause a "vulnerable" message.