CVE-2021-25689
📋 TL;DR
CVE-2021-25689 is a critical out-of-bounds write vulnerability in Teradici PCoIP soft client that allows remote code execution. Attackers can exploit this to take complete control of affected systems. Organizations using Teradici PCoIP soft client versions before 20.10.1 are vulnerable.
💻 Affected Systems
- Teradici PCoIP soft client
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the endpoint, enabling data theft, lateral movement, and persistent access.
Likely Case
Remote code execution leading to malware deployment, credential harvesting, and system compromise.
If Mitigated
Limited impact if proper network segmentation and endpoint protection are in place, though exploitation risk remains high.
🎯 Exploit Status
The vulnerability requires no authentication and has a low attack complexity, making it highly exploitable. No public proof-of-concept has been released.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 20.10.1 and later
Vendor Advisory: https://advisory.teradici.com/security-advisories/75/
Restart Required: Yes
Instructions:
1. Download Teradici PCoIP soft client version 20.10.1 or later from the official Teradici website. 2. Uninstall the previous version. 3. Install the updated version. 4. Restart the system.
🔧 Temporary Workarounds
Network segmentation
allRestrict network access to PCoIP clients to trusted networks only
Disable PCoIP client
allTemporarily disable or uninstall PCoIP soft client until patching is possible
🧯 If You Can't Patch
- Implement strict network segmentation to isolate PCoIP clients from untrusted networks
- Deploy endpoint detection and response (EDR) solutions to detect exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check the installed version of Teradici PCoIP soft client. If version is below 20.10.1, the system is vulnerable.Check Version:
On Windows: Check 'Add or Remove Programs' for Teradici PCoIP soft client version. On Linux/macOS: Check application version in the client interface or installation directory.Verify Fix Applied:
Verify that Teradici PCoIP soft client version is 20.10.1 or higher after installation.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from PCoIP client
- Memory access violations in system logs
- Crash reports from PCoIP client
Network Indicators:
- Unusual network traffic to/from PCoIP client ports
- Suspicious connections to PCoIP clients from untrusted sources
SIEM Query:
source="*pcoip*" AND (event_type="crash" OR process_name="*pcoip*")