CVE-2021-42704
📋 TL;DR
CVE-2021-42704 is an out-of-bounds write vulnerability in Inkscape 0.91 that could allow remote code execution when processing malicious files. This affects users of Inkscape 0.91, particularly those in industrial control systems using SCADA animation extensions. Attackers could exploit this by tricking users into opening specially crafted SVG files.
💻 Affected Systems
- Inkscape
📦 What is this software?
Inkscape by Inkscape
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the affected system, potentially leading to data theft, ransomware deployment, or lateral movement within networks.
Likely Case
Local privilege escalation or arbitrary code execution in the context of the user running Inkscape, allowing file system access and potential persistence mechanisms.
If Mitigated
Application crash or denial of service if memory corruption occurs but exploitation fails, with limited impact if proper sandboxing and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires user interaction to open malicious files. The vulnerability is in the core rendering engine, making reliable exploitation feasible but requiring specific file crafting.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 0.91 (0.92 and later)
Vendor Advisory: https://inkscape.org/release/
Restart Required: No
Instructions:
1. Download and install Inkscape 0.92 or later from inkscape.org. 2. Uninstall Inkscape 0.91. 3. Verify installation by checking Help > About Inkscape shows version 0.92 or higher.
🔧 Temporary Workarounds
Restrict file processing
allConfigure system to prevent Inkscape from processing untrusted SVG files
Application sandboxing
linux/windowsRun Inkscape in a sandboxed environment to limit potential damage
firejail inkscape (Linux)
sandboxie (Windows)
🧯 If You Can't Patch
- Implement strict file validation policies to prevent opening untrusted SVG files with Inkscape
- Deploy endpoint detection and response (EDR) solutions to monitor for suspicious Inkscape process behavior
🔍 How to Verify
Check if Vulnerable:
Open Inkscape, go to Help > About Inkscape, check if version is exactly 0.91Check Version:
inkscape --version (Linux/macOS) or check program properties (Windows)Verify Fix Applied:
After updating, verify Help > About Inkscape shows version 0.92 or higher📡 Detection & Monitoring
Log Indicators:
- Application crashes of inkscape.exe or inkscape process
- Unusual file access patterns from Inkscape process
- Creation of unexpected child processes from Inkscape
Network Indicators:
- Outbound connections from Inkscape process to unexpected destinations
- DNS queries for command and control domains from system running Inkscape
SIEM Query:
process_name:"inkscape.exe" AND (event_type:crash OR child_process_count > 3)