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.
Conclusion & alert: CVE-2017-6679 is rated Low Risk (35.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.37%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.10% | 0.37% | +0.27% |
| 2 | 2025-03-30 | 0.26% | 0.10% | -0.15% |
| 3 | 2025-03-29 | — | 0.26% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.4 | 3.1 | MEDIUM |
|
0.5 | 5.9 | [email protected] |
| 6.0 | 2.0 | MEDIUM |
|
1.5 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | umbrella_virtual_appliance | < 2.1.0 | cpe:2.3:a:cisco:umbrella_virtual_appliance:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://www.securityfocus.com/bid/101567 | Third Party Advisory VDB Entry |
| https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-tunnel-gJw5thgE | Vendor Advisory |
| https://support.umbrella.com/hc/en-us/articles/115004154423 | Third Party Advisory |
| https://support.umbrella.com/hc/en-us/articles/115004752143-Virtual-Appliance-Vulnerability-due-to-always-on-SSH-Tunnel-RESOLVED-2017-09-15 | Third Party Advisory |
| https://www.info-sec.ca/advisories/Cisco-Umbrella.html | Third Party Advisory |