CVE-2020-23931 – CVE-2020-23931 is a heap-based buffer over-read... (How to Fix)

Q: What is the severity of CVE-2020-23931?

CVE-2020-23931 has a CVSS score of 7.1 (HIGH). CVE-2020-23931 is a heap-based buffer over-read vulnerability in GPAC's abst_box_read function that allows reading beyond allocated memory boundaries. This affects systems running GPAC multimedia framework before version 1.0.1, potentially exposing sensitive data or causing crashes.

📋 TL;DR

CVE-2020-23931 is a heap-based buffer over-read vulnerability in GPAC's abst_box_read function that allows reading beyond allocated memory boundaries. This affects systems running GPAC multimedia framework before version 1.0.1, potentially exposing sensitive data or causing crashes.

💻 Affected Systems

Products:

GPAC Multimedia Framework

Versions: All versions before 1.0.1

Operating Systems: Linux, Windows, macOS, BSD

Default Config Vulnerable: ⚠️ Yes

Notes: Vulnerability triggers when processing specially crafted media files with Adobe-specific metadata boxes.

📦 What is this software?

Gpac by Gpac

View all CVEs affecting Gpac →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise if combined with other vulnerabilities, or sensitive information disclosure from process memory.

🟠

Likely Case

Application crash (denial of service) or limited information disclosure from adjacent heap memory.

🟢

If Mitigated

Application crash with no data loss if proper sandboxing and memory protections are enabled.

🌐 Internet-Facing: MEDIUM - Requires processing malicious media files, but GPAC is often used in media processing pipelines accessible via web interfaces.

🏢 Internal Only: LOW - Typically requires user interaction to process malicious files, though automated media processing systems could be vulnerable.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Proof-of-concept exists in GitHub issues, exploitation requires crafting specific media files but doesn't require authentication.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 1.0.1 and later

Vendor Advisory: https://github.com/gpac/gpac/commit/093283e727f396130651280609e687cd4778e0d1

Restart Required: Yes

Instructions:

1. Download GPAC 1.0.1 or later from official repository. 2. Compile and install following build instructions. 3. Restart any services using GPAC libraries.

🔧 Temporary Workarounds

Disable Adobe metadata processing

all

Modify GPAC configuration to skip processing of Adobe-specific metadata boxes

# Requires source code modification in box_code_adobe.c

Input validation for media files

all

Implement strict validation of media files before processing with GPAC

# Use file validation tools before passing to GPAC

🧯 If You Can't Patch

Isolate GPAC processes using containerization or sandboxing
Implement network segmentation to limit access to GPAC services

🔍 How to Verify

Check if Vulnerable:

Check GPAC version with 'gpac -version' or 'MP4Box -version' and verify it's below 1.0.1

Check Version:

gpac -version 2>/dev/null || MP4Box -version 2>/dev/null || echo "GPAC not found"

Verify Fix Applied:

Confirm version is 1.0.1 or higher and test with known proof-of-concept media files

📡 Detection & Monitoring

Log Indicators:

GPAC segmentation faults
Memory access violation errors
Abnormal process termination

Network Indicators:

Unusual media file uploads to processing services
Repeated connection attempts to media processing endpoints

SIEM Query:

process.name:"gpac" OR process.name:"MP4Box" AND (event.type:"crash" OR event.type:"segfault")

📊 Metadata

CVE ID: CVE-2020-23931

CVSS v3 Score: 7.1 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

CWE: CWE-125

Published: April 21, 2021

Last Updated: November 21, 2024

🔗 References

https://cwe.mitre.org/data/definitions/126.html Technical Description,Third Party Advisory
https://github.com/gpac/gpac/commit/093283e727f396130651280609e687cd4778e0d1 Patch,Third Party Advisory
https://github.com/gpac/gpac/issues/1564 Third Party Advisory
https://github.com/gpac/gpac/issues/1567 Third Party Advisory
https://cwe.mitre.org/data/definitions/126.html Technical Description,Third Party Advisory
https://github.com/gpac/gpac/commit/093283e727f396130651280609e687cd4778e0d1 Patch,Third Party Advisory
https://github.com/gpac/gpac/issues/1564 Third Party Advisory
https://github.com/gpac/gpac/issues/1567 Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2020-23931, you might also want to check these: