CVE-2023-4590
📋 TL;DR
A buffer overflow vulnerability in Frhed hex editor version 1.6.0 allows attackers to execute arbitrary code by exploiting a long filename argument through Structured Exception Handler (SEH) registers. This affects users who open malicious files with the vulnerable Frhed version. Successful exploitation could lead to complete system compromise.
💻 Affected Systems
- Frhed hex editor
📦 What is this software?
Frhed by Kimmov
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with SYSTEM/administrator privileges leading to full system compromise, data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Local privilege escalation or arbitrary code execution when a user opens a malicious file, potentially leading to malware infection or data exfiltration.
If Mitigated
Limited impact with proper application sandboxing, restricted user privileges, and security controls preventing execution of untrusted files.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious file). SEH-based buffer overflow exploitation is well-documented but requires specific payload construction.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.incibe.es/en/incibe-cert/notices/aviso/buffer-overflow-vulnerability-frhed
Restart Required: No
Instructions:
1. Uninstall Frhed 1.6.0. 2. Monitor vendor channels for patch availability. 3. Consider alternative hex editors until a fix is released.
🔧 Temporary Workarounds
Uninstall vulnerable version
windowsRemove Frhed 1.6.0 from affected systems
Control Panel > Programs > Uninstall Frhed 1.6.0
Restrict file execution
windowsPrevent execution of untrusted files through application control policies
🧯 If You Can't Patch
- Implement application whitelisting to block Frhed execution
- Run Frhed in a sandboxed environment with restricted privileges
🔍 How to Verify
Check if Vulnerable:
Check installed programs list for Frhed version 1.6.0Check Version:
wmic product where name="Frhed" get versionVerify Fix Applied:
Verify Frhed 1.6.0 is not installed or has been replaced with a newer version📡 Detection & Monitoring
Log Indicators:
- Process creation events for frhed.exe with suspicious command-line arguments
- Application crash logs from Frhed
Network Indicators:
- Unusual outbound connections from Frhed process
SIEM Query:
ProcessName="frhed.exe" AND (CommandLine CONTAINS "-f" OR CommandLine LENGTH > 100)