CVE-2020-37121
📋 TL;DR
CVE-2020-37121 is a critical buffer overflow vulnerability in CODE::BLOCKS IDE that allows remote code execution via specially crafted M3U playlist files. Attackers can exploit this by overwriting Structured Exception Handlers with Unicode characters to execute arbitrary shellcode. Users of CODE::BLOCKS 16.01 who open malicious M3U files are affected.
💻 Affected Systems
- CODE::BLOCKS
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the victim's machine, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Remote code execution with the privileges of the CODE::BLOCKS user, allowing file system access, credential harvesting, and installation of persistent malware.
If Mitigated
Limited impact if proper application whitelisting and file type restrictions prevent execution of malicious M3U files.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (ID 48344) and requires user interaction to open malicious file.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 20.03 or later
Vendor Advisory: https://www.codeblocks.org/
Restart Required: Yes
Instructions:
1. Download latest CODE::BLOCKS version from official website. 2. Uninstall current version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Disable M3U file association
allPrevent CODE::BLOCKS from automatically opening M3U files
Windows: assoc .m3u=
Linux: Remove .m3u from CODE::BLOCKS file associations
Application sandboxing
allRun CODE::BLOCKS in restricted environment
Windows: Use AppLocker to restrict CODE::BLOCKS execution
Linux: Use Firejail or similar sandboxing tools
🧯 If You Can't Patch
- Implement strict file type filtering to block M3U files at network perimeter and endpoint
- Use application control solutions to prevent CODE::BLOCKS from executing untrusted files
🔍 How to Verify
Check if Vulnerable:
Check CODE::BLOCKS version: Help → About → Version should be 16.01Check Version:
codeblocks --versionVerify Fix Applied:
Verify installed version is 20.03 or later via Help → About menu📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from CODE::BLOCKS
- Multiple failed attempts to open M3U files
- Suspicious network connections originating from CODE::BLOCKS process
Network Indicators:
- Unexpected outbound connections from CODE::BLOCKS
- M3U file downloads to endpoints running vulnerable version
SIEM Query:
process_name:"codeblocks.exe" AND (file_extension:".m3u" OR process_child_name: suspicious)