Undocumented tunnel support in Cisco Umbrella Virtual Appliance

1) Improper restriction of communication channel to intended endpoints

EUVDB-ID: #VU79657

Risk: Medium

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2017-6679

CWE-ID: CWE-923 - Improper Restriction of Communication Channel to Intended Endpoints

Exploit availability: No

Description

The vulnerability allows a remote user to compromise the affected system.

The vulnerability exists due to an undocumented support mechanism in the remote support feature of Cisco Umbrella Virtual Appliance. A remote user can obtain full control without explicit customer approval.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco Umbrella Virtual Appliance: before 2.1.0

CPE2.3

• cpe:2.3:a:cisco_systems:cisco_umbrella_virtual_appliance:*:*:*:*:*:*:*:*

External links

https://support.umbrella.com/hc/en-us/articles/115004154423
https://support.umbrella.com/hc/en-us/articles/115004752143-Virtual-Appliance-Vulnerability-due-to-always-on-SSH-Tunnel-RESOLVED-2017-09-15
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwh07325cisco-sa-umbrella-tunnel-gJw5thgE

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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