CVE-2021-1502
📋 TL;DR
This vulnerability allows remote code execution through malicious Webex recording files (ARF/WRF formats). An attacker can send a malicious file via email or link, and if opened by a user, execute arbitrary code with the user's privileges. Affects users of Cisco Webex Network Recording Player and Cisco Webex Player on Windows and macOS.
💻 Affected Systems
- Cisco Webex Network Recording Player
- Cisco Webex Player
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the targeted user, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Malware installation, credential theft, or data exfiltration from the compromised user's system.
If Mitigated
Limited impact if users avoid opening untrusted Webex files and proper endpoint protections are in place.
🎯 Exploit Status
Exploitation requires user interaction but is straightforward once malicious file is opened.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 41.5 or later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-player-dOJ2jOJ
Restart Required: Yes
Instructions:
1. Download latest version from Cisco Webex downloads page. 2. Install update. 3. Restart system.
🔧 Temporary Workarounds
Disable Webex Player file associations
allRemove file associations for .arf and .wrf files to prevent automatic opening with vulnerable player.
Windows: Use 'Default Programs' in Control Panel to change file associations
macOS: Right-click .arf/.wrf files → Get Info → Open With → Change to different application
🧯 If You Can't Patch
- Implement application whitelisting to block execution of Webex Player
- Educate users to never open Webex recording files from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Webex Player version in application settings or About dialog.Check Version:
Windows: Check Help → About in Webex Player. macOS: Webex Player → About Webex Player.Verify Fix Applied:
Confirm version is 41.5 or later after update.📡 Detection & Monitoring
Log Indicators:
- Process creation events for Webex Player with suspicious parent processes
- File access events for .arf/.wrf files from email clients or downloads
Network Indicators:
- Downloads of .arf/.wrf files from external sources
- Unusual outbound connections after Webex Player execution
SIEM Query:
process_name:"WebexPlayer.exe" AND parent_process_name IN ("outlook.exe", "chrome.exe", "firefox.exe")