CVE-2020-19491
📋 TL;DR
CVE-2020-19491 is an invalid memory access vulnerability in the cgif.c component of sam2p image conversion software that causes a segmentation fault when processing crafted input. This allows attackers to cause denial of service (crashing the application) and potentially execute arbitrary code. Users and systems running sam2p 0.49.4 for image processing are affected.
💻 Affected Systems
- sam2p
📦 What is this software?
Sam2p by Sam2p Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the memory corruption can be weaponized for arbitrary code execution.
Likely Case
Denial of service through application crash when processing malicious image files.
If Mitigated
Application crash with no further impact if proper sandboxing and privilege separation are implemented.
🎯 Exploit Status
The vulnerability requires feeding a crafted image file to sam2p. Proof-of-concept crash files are available in the GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 1d62cf8964bfcafa6561c4c3bb66d4aa4c529a73 and later versions
Vendor Advisory: https://github.com/pts/sam2p/commit/1d62cf8964bfcafa6561c4c3bb66d4aa4c529a73
Restart Required: No
Instructions:
1. Update sam2p to the latest version from GitHub. 2. Recompile from source if using self-compiled version. 3. Replace the vulnerable binary with the patched version.
🔧 Temporary Workarounds
Disable GIF processing
allConfigure systems to not use sam2p for GIF file processing
Input validation
allImplement file type validation before passing images to sam2p
🧯 If You Can't Patch
- Run sam2p in a sandboxed environment with minimal privileges
- Implement strict input validation and file size limits for images processed by sam2p
🔍 How to Verify
Check if Vulnerable:
Check sam2p version: sam2p --version. If it shows 0.49.4, the system is vulnerable.Check Version:
sam2p --versionVerify Fix Applied:
Update to latest version and test with known malicious GIF files from GitHub issues to ensure no crash occurs.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault errors in system logs
- sam2p process crashes
- Core dumps from sam2p
Network Indicators:
- Unusual image file uploads to systems using sam2p
SIEM Query:
process_name="sam2p" AND (event_type="crash" OR exit_code=139)