libevent: User-assisted execution of arbitrary code

Background

libevent is a library to execute a function when a specific event occurs on a file descriptor.

Description

Multiple integer overflow errors in libevent could cause a heap-based buffer overflow.

Impact

A context-dependent attacker could cause an application linked against libevent to pass an excessively long input through evbuffer, possibly resulting in execution of arbitrary code with the privileges of the process or a Denial of Service condition.

Workaround

There is no known workaround at this time.

Resolution

All libevent users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-libs/libevent-2.0.22"