CVE-2017-6679

Name: CVE-2017-6679
Creator: NVD / NIST
Published: 2017-12-01T17:29:00.667+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.4/10EPSS 0.36%

Last modified Jun 22, 2026

CVE-2017-6679 is a medium-severity vulnerability rated 6.4/10 on the CVSS scale. The Cisco Umbrella Virtual Appliance Version 2.0.3 and prior contained an undocumented encrypted remote support tunnel (SSH) which auto initiated from the customer's appliance to Cisco's SSH Hubs in the Umbrella datacenters. These tunnels were primarily leveraged for remote support and allowed for authorized/authenticated personnel from the Cisco Umbrella team to access the appliance remotely and obtain full control without explicit customer approval. EPSS estimates a 0.36% chance of exploitation in the next 30 days.

Description

The Cisco Umbrella Virtual Appliance Version 2.0.3 and prior contained an undocumented encrypted remote support tunnel (SSH) which auto initiated from the customer's appliance to Cisco's SSH Hubs in the Umbrella datacenters. These tunnels were primarily leveraged for remote support and allowed for authorized/authenticated personnel from the Cisco Umbrella team to access the appliance remotely and obtain full control without explicit customer approval. To address this vulnerability, the Umbrella Virtual Appliance version 2.1.0 now requires explicit customer approval before an SSH tunnel from the VA to the Cisco terminating server can be established.

Metrics

CVSS 3.1

6.4/10

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.36%

27.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Cisco	Umbrella Virtual Appliance	< 2.1.0

References

http://www.securityfocus.com/bid/101567Third Party Advisory, VDB Entry
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-tunnel-gJw5thgEVendor Advisory
https://support.umbrella.com/hc/en-us/articles/115004154423Third Party Advisory
https://support.umbrella.com/hc/en-us/articles/115004752143-Virtual-Appliance-Vulnerability-due-to-always-on-SSH-Tunnel-RESOLVED-2017-09-15Third Party Advisory
https://www.info-sec.ca/advisories/Cisco-Umbrella.htmlThird Party Advisory
http://www.securityfocus.com/bid/101567Third Party Advisory, VDB Entry
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-tunnel-gJw5thgEVendor Advisory
https://support.umbrella.com/hc/en-us/articles/115004154423Third Party Advisory
https://support.umbrella.com/hc/en-us/articles/115004752143-Virtual-Appliance-Vulnerability-due-to-always-on-SSH-Tunnel-RESOLVED-2017-09-15Third Party Advisory
https://www.info-sec.ca/advisories/Cisco-Umbrella.htmlThird Party Advisory

Timeline

Published: Dec 1, 2017
Last Modified: Jun 22, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2017-6679?

How severe is CVE-2017-6679?

CVE-2017-6679 has a CVSS score of 6.4/10 (MEDIUM severity). The EPSS model estimates a 0.36% probability of exploitation in the next 30 days.

How do I fix CVE-2017-6679?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-6679?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST