Executive brief
A vulnerability in the management interface of the Cisco Umbrella Virtual Appliance could allow an authorized user to gain full administrative control (root privileges) over the system. Cisco Umbrella is a cloud-delivered security service, and the Virtual Appliance component helps manage local network traffic. If exploited, an attacker who already has limited administrative access could bypass security restrictions to modify system configurations or access sensitive data.
Technical details
A privilege escalation vulnerability exists in the vmadmin Command Line Interface (CLI) of the Cisco Umbrella Virtual Appliance. The root cause is improper validation of user-supplied input when executing certain CLI commands (CWE-269). An attacker with existing 'vmadmin' level privileges can exploit this flaw by executing specifically crafted commands to bypass restricted shell environments. Successful exploitation allows the attacker to elevate their privileges to the root user. The vulnerability is local in nature, requiring the attacker to have an established authenticated session on the appliance. Cisco has addressed this in version 3.8.5.
Affected products
- Cisco Umbrella Virtual Appliance Earlier than 3.8.5
Timeline
- 2026-06-17: disclosed
- 2026-06-17: advisory
- 2026-06-17: patched