Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [day] [month] [year] [list]
Date: Tue, 29 Sep 2015 17:44:23 +0200
From: Tyler Hicks <>
Cc: Roman Fiedler <>,
	Serge Hallyn <>,
	St├ęphane Graber <>
Subject: Security issue in LXC (CVE-2015-1335)

Roman Fiedler discovered a directory traversal flaw that can occur while
lxc-start is initially setting up the mounts for a container.

If an attacker constructs a malicious symlink in the target path of a
container mount point, the symlink could be mishandled the next time the
container is started and the mount operation may be performed at an
undesired target location.

Additionally, if the source path of the mount is a malicious symlink
relative to the container, the symlink could be mishandled to bind mount
an undesired file or directory into the container.

Direct modification of the host's mount table is not possible since a
slave copy of the mount table is used.

An example of an attack that is made possible by this flaw is a user
inside of the container could leave behind a malicious symlink, at a
mount point target under their control, that would cause /proc/self/attr
to be mounted over. lxc-start would then unknowingly write to a "fake"
/proc/self/attr/current file, prior to launching the container init, to
perform an AppArmor profile transition. The profile transition would not
occur and the container init would run under incorrect confinement.

Upstream announcement:


[ CONTENT OF TYPE application/pgp-signature SKIPPED ]

Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Powered by Openwall GNU/*/Linux - Powered by OpenVZ