USN-6762-1: GNU C Library vulnerabilities

Recent discoveries have exposed multiple vulnerabilities in the GNU C Library, specifically impacting systems running Ubuntu 14.04 LTS. These vulnerabilities, identified by various CVEs, pose significant security risks, potentially allowing attackers to cause system crashes or execute arbitrary code. This article seeks to provide precise details on each of these vulnerabilities and suggests immediate actions for users.

The first vulnerability, labeled CVE-2014-9984, involves incorrect buffer size computations by nscd while processing netgroup requests in versions before 2.20 of glibc. This flaw could lead to daemon crashes or unauthorized code execution.

Another vulnerability, CVE-2015-20109, relates to a denial of service (DoS) situation created by end_pattern in versions prior to 2.22 of glibc. This incident could crash an application, thanks to improper handling of specific patterns by the internal_fnmatch.

The third disclosure, CVE-2018-11236, addresses a buffer overflow risk stemming from an integer overflow when glibc processes overly long pathname arguments to the realpath function in versions up to 2.27. This particularly affects 32-bit architectures, leading potentially to arbitrary code execution.

Most recently, a CVE-2021-3999 has been flagged due to an off-by-one buffer overflow in glibc's getcwd function, which might result in memory corruption when the buffer size is exactly one. This vulnerability primarily endangers systems where local attackers can manipulate inputs in a setuid program, possibly escalating privileges through arbitrary code execution.

This sequence of vulnerabilities underscores the importance of maintaining updated systems and the deployment of patches promptly. For more detailed information and to access necessary patches, please visit LinuxPatch.

All users running Ubuntu 14.04 LTS are immensely encouraged to assess their systems and apply all relevant security patches to hinder potential exploits designed around these vulnerabilities. Tackling these vulnerabilities head-on is essential for maintaining operational integrity and safeguarding data against unauthorized access and system failures.