Cisco Umbrella VA
CVE-2026-20246
MEDIUM
Severity by source
AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Requires local CLI access and vmadmin credentials (AV:L, PR:H); root escalation yields full C and I impact with no availability disruption described.
Primary rating from Vendor (cisco).
CVSS VectorVendor: cisco
Lifecycle Timeline
2DescriptionCVE.org
A vulnerability in the vmadmin CLI of Cisco Umbrella Virtual Appliance could allow an authenticated, local attacker to elevate privileges on an affected device.
This vulnerability is due to insufficient validation of user-supplied commands. An attacker with vmadmin privileges could exploit this vulnerability by using certain commands at the CLI. A successful exploit could allow the attacker to elevate privileges to root.
AnalysisAI
Privilege escalation in the Cisco Umbrella Virtual Appliance vmadmin CLI enables an authenticated local attacker holding vmadmin-level credentials to elevate access to root on the affected device. The flaw, classified as CWE-269 (Improper Privilege Management), arises because the vmadmin CLI does not adequately validate or restrict specific commands that can be leveraged as a privilege escalation path. No public exploit code has been identified and the CVE is not listed in the CISA KEV catalog at time of analysis; the CVSS 6.0 Medium score reflects the high-privilege prerequisite that meaningfully constrains the realistic attacker pool.
Technical ContextAI
The affected component is the vmadmin CLI of the Cisco Umbrella Virtual Appliance, an on-premises DNS-layer security proxy deployed alongside the Cisco Umbrella cloud service. The vmadmin role is a purpose-built restricted administrative account intended to manage appliance configuration without granting full OS root access - a common least-privilege pattern for network appliances. The affected product is identified by CPE cpe:2.3:a:cisco:cisco_umbrella_insights_virtual_appliance:*:*:*:*:*:*:*:*, with the wildcard version field indicating all tracked versions may be affected. The root cause is CWE-269 (Improper Privilege Management): the CLI wrapper fails to sufficiently sandbox or validate the commands available to the vmadmin role, allowing those commands to serve as a controlled escalation vector. This class of bug commonly manifests in restricted shell environments, sudo rule misconfigurations, or CLI interpreters that expose privileged OS operations to non-root accounts without adequate filtering.
RemediationAI
The primary remediation is to apply the update detailed in Cisco Security Advisory cisco-sa-umbrella-priv-esc-F4wJB7AU, available at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-umbrella-priv-esc-F4wJB7AU - exact fixed version numbers are not confirmed in available intelligence and must be retrieved directly from the advisory. As a compensating control prior to patching, restrict vmadmin CLI access to the minimum number of explicitly trusted administrators and enforce credential management controls (unique, rotated credentials, MFA where supported) to reduce insider-threat and credential-theft exposure; be aware this does not eliminate the vulnerability but raises the bar for exploitation. Additionally, enable audit logging of vmadmin CLI sessions and alert on anomalous command sequences, which can provide detection capability without operational disruption. Note that restricting vmadmin access may impair routine appliance administration workflows and should be coordinated with operational teams before implementation.
Same weakness CWE-269 – Improper Privilege Management
View allSame technique Privilege Escalation
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External POC / Exploit Code
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