CVE-2020-3588
📋 TL;DR
A local privilege escalation vulnerability in Cisco Webex Meetings Desktop App for Windows allows attackers to execute arbitrary code when deployed in virtual desktop environments. This affects users running Webex in hosted virtual desktop configurations with the virtual desktop plug-in enabled. Attackers with limited local privileges can exploit improper message validation to gain elevated system access.
💻 Affected Systems
- Cisco Webex Meetings Desktop App for Windows
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains full system control, installs persistent malware, steals credentials, and pivots to other systems in the network.
Likely Case
Local attacker elevates privileges to install keyloggers, steal sensitive data, or establish persistence on the compromised system.
If Mitigated
Attack fails due to proper patch deployment, virtual desktop isolation, or lack of required configuration.
🎯 Exploit Status
Requires local access and specific virtual desktop configuration. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 40.6.0 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-vdi-qQrpBwuJ
Restart Required: Yes
Instructions:
1. Download Webex Meetings Desktop App version 40.6.0 or later from Cisco's official site. 2. Install the update on all affected virtual desktops. 3. Restart the application or system as required.
🔧 Temporary Workarounds
Disable Virtual Desktop Plug-in
windowsRemove or disable the Cisco Webex Meetings virtual desktop plug-in for thin clients in virtual desktop environments.
Uninstall via Control Panel > Programs and Features > Cisco Webex Meetings virtual desktop plug-in
Restrict Local Access
allImplement strict access controls on virtual desktop environments to limit local user privileges.
🧯 If You Can't Patch
- Isolate virtual desktop environments from critical network segments
- Implement application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Webex version in Help > About Webex Meetings. If version is below 40.6.0 and virtual desktop plug-in is installed, system is vulnerable.Check Version:
In Webex Meetings: Help > About Webex MeetingsVerify Fix Applied:
Confirm version is 40.6.0 or higher in Help > About Webex Meetings and verify virtual desktop plug-in is either updated or disabled.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from Webex processes
- Failed privilege escalation attempts in Windows Event Logs
Network Indicators:
- Unusual outbound connections from virtual desktop systems
SIEM Query:
Process creation where parent_process contains 'webex' and process_name contains 'cmd.exe' or 'powershell.exe'