Permissions, Privileges, and Access Controls in LXS

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU31423

Risk: High

CVSSv3.1: 7.9 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-8649

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote privileged user to execute arbitrary code.

lxc-attach in LXC before 1.0.9 and 2.x before 2.0.6 allows an attacker inside of an unprivileged container to use an inherited file descriptor, of the host's /proc, to access the rest of the host's filesystem via the openat() family of syscalls.

Mitigation

Install update from vendor's website.

Vulnerable software versions

LXS: 2.0.0 - 2.0.5

External links

http://www.securityfocus.com/bid/94498
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=845465
http://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1639345
http://bugzilla.redhat.com/show_bug.cgi?id=1398242
http://github.com/lxc/lxc/commit/81f466d05f2a89cb4f122ef7f593ff3f279b165c
http://security-tracker.debian.org/tracker/CVE-2016-8649

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted file.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.