Information disclosure in LXC

1) Information disclosure

EUVDB-ID: #VU14510

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-6556

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

Exploit availability: No

Description

The vulnerability allows a local unauthenticated attacker to obtain potentially sensitive information on the target system.

The weakness exists due to lxc-user-nic unconditionally opens a user provided path when asked to delete a network interface. A local attacker can check for the existence of a path which he wouldn't otherwise be able to reach and trigger side effects by causing a (read-only) open of special kernel files (ptmx, proc, sys).

Mitigation

Update to version 3.0.2.

Vulnerable software versions

LXS: 2.0.0 - 3.0.1

CPE2.3

• cpe:2.3:a:linux_containers:lxc:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:linux_containers:lxc:2.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:linux_containers:lxc:2.0.2:*:*:*:*:*:*:*

External links

https://bugzilla.suse.com/show_bug.cgi?id=988348

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

How the attacker can exploit this vulnerability?

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

The attacker would have to login to the system and perform certain actions in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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