CVE-2023-39943
📋 TL;DR
This vulnerability in Ashlar-Vellum Cobalt allows attackers to execute arbitrary code by exploiting improper validation when parsing XE files. It affects users of Cobalt versions before v12 SP2 Build 1204.200. Successful exploitation could lead to complete system compromise.
💻 Affected Systems
- Ashlar-Vellum Cobalt
📦 What is this software?
Cobalt by Ashlar
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the Cobalt process, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation or remote code execution if XE files can be delivered to target systems via phishing or other attack vectors.
If Mitigated
Limited impact with proper network segmentation, application sandboxing, and user privilege restrictions in place.
🎯 Exploit Status
Exploitation requires crafting malicious XE files and getting them parsed by vulnerable Cobalt instances.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v12 SP2 Build 1204.200 or later
Vendor Advisory: https://www.cisa.gov/news-events/ics-advisories/icsa-23-299-03
Restart Required: No
Instructions:
1. Download the latest version from Ashlar-Vellum. 2. Install the update following vendor instructions. 3. Verify the version is 1204.200 or higher.
🔧 Temporary Workarounds
Restrict XE file processing
allBlock or restrict processing of XE files in Cobalt through application settings or policies.
Application sandboxing
allRun Cobalt in a sandboxed environment with limited permissions.
🧯 If You Can't Patch
- Implement strict access controls to limit who can run Cobalt and process XE files.
- Use application whitelisting to prevent execution of unauthorized code that might result from exploitation.
🔍 How to Verify
Check if Vulnerable:
Check Cobalt version in Help > About or similar menu. If version is below 1204.200, the system is vulnerable.Check Version:
Check application interface or consult vendor documentation for version checking commands.Verify Fix Applied:
Confirm version is 1204.200 or higher after applying the update.📡 Detection & Monitoring
Log Indicators:
- Unexpected crashes of Cobalt application
- Unusual file parsing errors in application logs
- Process creation from Cobalt with suspicious command lines
Network Indicators:
- Unusual outbound connections from Cobalt process
- File transfers of XE files to vulnerable systems
SIEM Query:
Process creation where parent process contains 'cobalt' AND (command line contains suspicious patterns OR destination IP is external)