CVE-2019-18826
📋 TL;DR
This vulnerability allows attackers to perform man-in-the-middle attacks by exploiting improper certificate chain validation in Barco ClickShare Button devices. Attackers could intercept and manipulate communications between the device and connected systems. Organizations using ClickShare Button R9861500D01 devices before firmware version 1.9.0 are affected.
💻 Affected Systems
- Barco ClickShare Button R9861500D01
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of ClickShare Button functionality allowing interception of all communications, credential theft, and potential lateral movement to connected systems.
Likely Case
Man-in-the-middle attacks leading to interception of sensitive meeting data, presentation content, and authentication credentials.
If Mitigated
Limited impact with proper network segmentation and monitoring, though certificate validation failures could still cause service disruption.
🎯 Exploit Status
Certificate validation bypass vulnerabilities are commonly exploited using standard man-in-the-middle techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.9.0 and later
Vendor Advisory: https://www.barco.com/en/clickshare/firmware-update
Restart Required: Yes
Instructions:
1. Download firmware version 1.9.0 or later from Barco's website. 2. Connect to the ClickShare Button via USB. 3. Run the firmware update utility. 4. Follow on-screen instructions to complete the update. 5. Verify the firmware version after completion.
🔧 Temporary Workarounds
Network segmentation
allIsolate ClickShare Button devices on a separate VLAN to limit potential attack surface.
Disable unused features
allDisable any unnecessary network services on the ClickShare Button if supported.
🧯 If You Can't Patch
- Physically isolate vulnerable devices from critical networks
- Implement strict network monitoring for certificate validation failures and unusual traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check the firmware version on the ClickShare Button device via its management interface or connected computer.Check Version:
Connect to ClickShare Button and check firmware version in device settings or management interface.Verify Fix Applied:
Confirm firmware version is 1.9.0 or higher and test certificate validation with controlled man-in-the-middle tests.📡 Detection & Monitoring
Log Indicators:
- Certificate validation failures
- Unexpected certificate authorities
- SSL/TLS handshake anomalies
Network Indicators:
- Unusual certificate chains in TLS connections
- Man-in-the-middle attack patterns
- SSL stripping attempts
SIEM Query:
source="clickshare" AND (event_type="certificate_error" OR event_type="ssl_handshake_failure")