CVE-2023-20093
📋 TL;DR
This vulnerability allows authenticated local attackers with remote support accounts to overwrite arbitrary files on Cisco TelePresence CE and RoomOS devices via symbolic link attacks. The issue stems from improper file access controls in the CLI. Only devices with vulnerable software versions are affected.
💻 Affected Systems
- Cisco TelePresence CE
- Cisco RoomOS
📦 What is this software?
Roomos by Cisco
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through overwriting critical system files, potentially leading to persistent backdoors, service disruption, or credential theft.
Likely Case
Local privilege escalation or service disruption by overwriting configuration files, potentially gaining administrative access.
If Mitigated
Limited impact if proper access controls restrict remote support accounts and file permissions are properly configured.
🎯 Exploit Status
Requires authenticated local access with remote support privileges and ability to place symbolic links in specific locations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cisco advisory for specific patched versions
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-roomos-file-write-rHKwegKf
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions. 2. Download appropriate software update from Cisco. 3. Apply update following Cisco's deployment procedures. 4. Restart affected devices.
🧯 If You Can't Patch
- Restrict access to remote support accounts and monitor for unauthorized usage.
- Implement strict file permission controls and monitor for symbolic link creation in sensitive directories.
🔍 How to Verify
Check if Vulnerable:
Check device software version against Cisco advisory and verify if remote support accounts exist.Check Version:
Check device web interface or CLI for software version information (specific command varies by device).Verify Fix Applied:
Verify software version has been updated to patched version listed in Cisco advisory.📡 Detection & Monitoring
Log Indicators:
- Unusual file modification events in system logs
- Multiple failed or successful authentication attempts to remote support accounts
- Symbolic link creation in system directories
Network Indicators:
- Unusual SSH or management traffic to affected devices
SIEM Query:
Search for: 'file overwrite', 'symbolic link creation', 'remote support login' events on Cisco TelePresence devices