sudo: Privilege escalation — GLSA 201705-15

A vulnerability in sudo allows local users to gain root privileges.

Affected Packages

app-admin/sudo on all architectures
Affected versions < 1.8.20_p1
Unaffected versions >= 1.8.20_p1

Background

sudo (su “do”) allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.

Description

Qualys discovered a vulnerability in sudo’s get_process_ttyname() for Linux, that via sudo_ttyname_scan() can be directed to use a user-controlled, arbitrary tty device during its traversal of “/dev” by utilizing the world-writable /dev/shm.

Impact

A local attacker can pretend that his tty is any character device on the filesystem, and after two race conditions, an attacker can pretend that the controlled tty is any file on the filesystem allowing for privilege escalation

Workaround

There is no known workaround at this time.

Resolution

All sudo users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-admin/sudo-1.8.20_p1"
 

References

Release Date
May 30, 2017

Latest Revision
May 30, 2017: 1

Severity
high

Exploitable
local

Bugzilla entries