CVE-2020-19499
📋 TL;DR
This vulnerability in libheif's Box_iref::get_references function allows attackers to trigger an invalid memory read, potentially causing denial of service or arbitrary code execution. It affects applications that process HEIF/HEIC image files using vulnerable versions of libheif. Any system or application using libheif to handle HEIF/HEIC images is potentially vulnerable.
💻 Affected Systems
- libheif
- Applications using libheif library
📦 What is this software?
Libheif by Struktur
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if memory corruption can be controlled to execute arbitrary code.
Likely Case
Denial of service causing application crashes when processing malicious HEIF/HEIC files.
If Mitigated
Application crash without privilege escalation if memory protections (ASLR, DEP) are effective.
🎯 Exploit Status
Proof of concept exists in GitHub issues. Exploitation requires processing a malicious HEIF/HEIC file, which can be delivered via email, web uploads, or other file transfer methods.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: libheif 1.4.0 with commit f7399b62d7fbc596f1b2871578c1d2053bedf1dd or later
Vendor Advisory: https://github.com/strukturag/libheif/commit/f7399b62d7fbc596f1b2871578c1d2053bedf1dd
Restart Required: Yes
Instructions:
1. Update libheif to version with commit f7399b62d7fbc596f1b2871578c1d2053bedf1dd or later. 2. Rebuild applications using libheif. 3. Restart affected services.
🔧 Temporary Workarounds
Disable HEIF/HEIC processing
allConfigure applications to reject or not process HEIF/HEIC files
Use file type filtering
allImplement strict file type validation to block HEIF/HEIC files at network boundaries
🧯 If You Can't Patch
- Implement strict input validation for HEIF/HEIC files
- Isolate image processing services in containers or VMs with limited privileges
🔍 How to Verify
Check if Vulnerable:
Check libheif version: `libheif --version` or check package manager. If version is 1.4.0 without patch commit, it's vulnerable.Check Version:
libheif --version 2>/dev/null || dpkg -l | grep libheif || rpm -qa | grep libheifVerify Fix Applied:
Verify libheif version includes commit f7399b62d7fbc596f1b2871578c1d2053bedf1dd: `git log --oneline | grep f7399b62`📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing image files
- Memory access violation errors
- Segmentation faults in libheif processes
Network Indicators:
- Unusual HEIF/HEIC file uploads
- Multiple failed image processing attempts
SIEM Query:
source="application.log" AND ("segmentation fault" OR "memory access violation" OR "libheif")