OpenSSH, Dropbear: Insecure use of system() call — GLSA 200602-11

A flaw in OpenSSH and Dropbear allows local users to elevate their privileges via scp.

Affected Packages

net-misc/openssh on all architectures
Affected versions < 4.2_p1-r1
Unaffected versions >= 4.2_p1-r1
net-misc/dropbear on all architectures
Affected versions < 0.47-r1
Unaffected versions >= 0.47-r1

Background

OpenSSH is a free application suite consisting of server and clients that replace tools like telnet, rlogin, rcp and ftp with more secure versions offering additional functionality. Dropbear is an SSH server and client designed with a small memory footprint that includes OpenSSH scp code.

Description

To copy from a local filesystem to another local filesystem, scp constructs a command line using 'cp' which is then executed via system(). Josh Bressers discovered that special characters are not escaped by scp, but are simply passed to the shell.

Impact

By tricking other users or applications to use scp on maliciously crafted filenames, a local attacker user can execute arbitrary commands with the rights of the user running scp.

Workaround

There is no known workaround at this time.

Resolution

All OpenSSH users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-misc/openssh-4.2_p1-r1"

All Dropbear users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-misc/dropbear-0.47-r1"

References

Release Date
February 20, 2006

Latest Revision
February 20, 2006: 01

Severity
low

Exploitable
local

Bugzilla entries