CVE-2020-24742
📋 TL;DR
CVE-2020-24742 is a path traversal vulnerability in Qt's QPluginLoader that loads plugins from the current working directory instead of secure locations. This allows attackers to execute arbitrary code by placing malicious plugin files where Qt applications run. Applications using Qt 5.14.0 for plugin loading are affected.
💻 Affected Systems
- Qt-based applications using QPluginLoader
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, and lateral movement within the network.
Likely Case
Local privilege escalation or arbitrary code execution when users run Qt applications from untrusted directories.
If Mitigated
Limited impact if applications run with minimal privileges and from controlled directories.
🎯 Exploit Status
Exploitation requires placing malicious plugin files in the working directory where Qt applications execute. No authentication needed if attacker can write to that directory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Qt 5.14.1 and later
Vendor Advisory: https://codereview.qt-project.org/c/qt/qtbase/+/280730
Restart Required: Yes
Instructions:
1. Upgrade Qt to version 5.14.1 or later. 2. Recompile affected applications with the updated Qt library. 3. Redeploy patched applications. 4. Restart services using Qt.
🔧 Temporary Workarounds
Restrict working directory permissions
linuxPrevent unauthorized users from writing to directories where Qt applications run.
chmod 755 /path/to/application/directory
chown root:root /path/to/application/directory
Run applications from secure directories
allEnsure Qt applications only execute from trusted, write-protected directories.
🧯 If You Can't Patch
- Implement strict file system permissions to prevent unauthorized writes to application directories
- Use application sandboxing or containerization to limit impact of potential exploitation
🔍 How to Verify
Check if Vulnerable:
Check Qt version in use: applications using Qt 5.14.0 with QPluginLoader functionality are vulnerable.Check Version:
qmake --version (for development) or check application dependenciesVerify Fix Applied:
Verify Qt version is 5.14.1 or later and applications have been recompiled with the updated library.📡 Detection & Monitoring
Log Indicators:
- Unexpected plugin loading from non-standard directories
- Application crashes during plugin initialization
Network Indicators:
- Unusual outbound connections from Qt applications post-startup
SIEM Query:
Process execution logs showing Qt applications running from unusual directories OR file creation events for plugin files in application directories