CVE-2015-8777

Publication date 20 January 2016

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

The process_envvars function in elf/rtld.c in the GNU C Library (aka glibc or libc6) before 2.23 allows local users to bypass a pointer-guarding protection mechanism via a zero value of the LD_POINTER_GUARD environment variable.

From the Ubuntu Security Team

Hector Marco and Ismael Ripoll discovered that the GNU C Library allowed the pointer-guarding protection mechanism to be disabled by honoring the LD_POINTER_GUARD environment variable across privilege boundaries. An local attacker could use this to exploit an existing vulnerability more easily.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
eglibc	17.04 zesty	Not in release
	16.10 yakkety	Not in release
	16.04 LTS xenial	Not in release
	15.10 wily	Not in release
	15.04 vivid	Not in release
	14.04 LTS trusty	Fixed 2.19-0ubuntu6.8
	12.04 LTS precise	Fixed 2.15-0ubuntu10.14
glibc	17.04 zesty	Not affected
	16.10 yakkety	Not affected
	16.04 LTS xenial	Not affected
	15.10 wily	Fixed 2.21-0ubuntu4.2
	15.04 vivid	Ignored end of life
	14.04 LTS trusty	Not in release
	12.04 LTS precise	Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
glibc	Upstream: https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commit;h=a014cecd82b71b70a6a843e250e06b541ad524f7

Severity score breakdown

Parameter	Value
Base score	5.5 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	High
Availability impact	None
Vector	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

USN-2985-1
GNU C Library vulnerabilities
25 May 2016