CVE-2020-35981
📋 TL;DR
This vulnerability in GPAC multimedia framework allows attackers to cause denial of service or potentially execute arbitrary code by exploiting an invalid pointer dereference in the SetupWriters() function. It affects systems running GPAC versions 0.8.0 and 1.0.1 that process malicious media files. Users and applications that utilize GPAC for media processing are at risk.
💻 Affected Systems
- GPAC Multimedia Framework
📦 What is this software?
Gpac by Gpac
Gpac by Gpac
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the pointer dereference can be manipulated to execute arbitrary code.
Likely Case
Application crash and denial of service when processing specially crafted media files.
If Mitigated
Limited to application crash with proper sandboxing and privilege separation in place.
🎯 Exploit Status
Exploitation requires crafting a malicious media file that triggers the pointer dereference. No public proof-of-concept has been released, but the vulnerability is well-documented in the GPAC repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit dae9900580a8888969481cd72035408091edb11b
Vendor Advisory: https://github.com/gpac/gpac/commit/dae9900580a8888969481cd72035408091edb11b
Restart Required: Yes
Instructions:
1. Update GPAC to the latest version from the official repository. 2. Recompile any applications using GPAC libraries. 3. Restart services using GPAC.
🔧 Temporary Workarounds
Disable vulnerable media processing
allTemporarily disable processing of media files through GPAC until patched.
# Disable GPAC services if running as daemon
sudo systemctl stop gpac-service
# Or disable media file uploads in applications
🧯 If You Can't Patch
- Implement strict input validation for media files and reject suspicious or malformed files.
- Run GPAC in a sandboxed environment with minimal privileges to limit potential damage.
🔍 How to Verify
Check if Vulnerable:
Check GPAC version: gpac -version. If output shows 0.8.0 or 1.0.1, the system is vulnerable.Check Version:
gpac -version 2>/dev/null || echo 'GPAC not installed'Verify Fix Applied:
Update GPAC and verify version is newer than 1.0.1 or includes commit dae9900580a8888969481cd72035408091edb11b.📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults in GPAC processes
- Error logs mentioning isomedia/isom_store.c or SetupWriters()
Network Indicators:
- Unusual media file uploads to applications using GPAC
SIEM Query:
process_name:gpac AND (event_type:crash OR exit_code:139)