glibc: getgrouplist buffer overflow vulnerability

Background

glibc is the GNU C library.

Description

A bug in the getgrouplist function can cause a buffer overflow if the size of the group list is too small to hold all the user’s groups. This overflow can cause segmentation faults in user applications. This vulnerability exists only when an administrator has placed a user in a number of groups larger than that expected by an application.

Impact

Applications that use getgrouplist can crash.

Workaround

There is no known workaround at this time.

Resolution

It is recommended that all Gentoo Linux users update their systems as follows:

 # emerge sync
 # emerge -pv '>=sys-libs/glibc-2.2.5'
 # emerge '>=sys-libs/glibc-2.2.5'
 # emerge clean