CVE-2023-40968
📋 TL;DR
A buffer overflow vulnerability in timg v1.5.1 and earlier allows remote attackers to cause denial of service by exploiting memory corruption at a specific address. This affects users who process untrusted image files with vulnerable timg versions. The vulnerability can be triggered remotely without authentication.
💻 Affected Systems
- timg (Terminal Image Viewer)
📦 What is this software?
Timg by Hzeller
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the buffer overflow can be controlled to execute arbitrary code.
Likely Case
Denial of service causing the timg application to crash when processing malicious image files.
If Mitigated
No impact if patched version is used or if timg is not exposed to untrusted input sources.
🎯 Exploit Status
Exploitation requires crafting a malicious image file that triggers the buffer overflow at the specific memory address.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.5.2
Vendor Advisory: https://github.com/hzeller/timg/releases/tag/v1.5.2
Restart Required: No
Instructions:
1. Download timg v1.5.2 from GitHub releases. 2. Uninstall old version. 3. Install new version following platform-specific build instructions. 4. Verify installation with version check.
🔧 Temporary Workarounds
Restrict image processing
allLimit timg to process only trusted image files from known sources
Network isolation
allEnsure timg is not accessible from untrusted networks
🧯 If You Can't Patch
- Remove timg from systems where it's not essential
- Implement strict input validation and sandboxing for timg processes
🔍 How to Verify
Check if Vulnerable:
Check timg version with 'timg --version' and compare against affected versions (v1.5.1 and earlier)Check Version:
timg --versionVerify Fix Applied:
Confirm version is v1.5.2 or later using 'timg --version'📡 Detection & Monitoring
Log Indicators:
- Segmentation fault errors
- Application crashes when processing images
- Memory access violation logs
Network Indicators:
- Unusual image file uploads to services using timg
- Repeated connection attempts to timg services
SIEM Query:
process_name:timg AND (event_type:crash OR error_message:"segmentation fault")