CVE-2022-33027 – LibreDWG v0.12.4.4608 contains a heap-use-after... (How to Fix)

📋 TL;DR

LibreDWG v0.12.4.4608 contains a heap-use-after-free vulnerability in the dwg_add_handleref function that could allow attackers to execute arbitrary code or cause denial of service. This affects applications using LibreDWG to process DWG files, including CAD software and file converters. Users who open malicious DWG files are at risk.

💻 Affected Systems

Products:

LibreDWG

Versions: v0.12.4.4608 specifically, potentially earlier versions with same code

Operating Systems: All platforms running LibreDWG

Default Config Vulnerable: ⚠️ Yes

Notes: Any application using LibreDWG library to parse DWG files is vulnerable

📦 What is this software?

Libredwg by Gnu

View all CVEs affecting Libredwg →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise if exploited via malicious DWG file processing

🟠

Likely Case

Application crash or denial of service when processing specially crafted DWG files

🟢

If Mitigated

Limited impact if file processing occurs in sandboxed environment with proper memory protections

🌐 Internet-Facing: MEDIUM - Requires user interaction to open malicious files, but web applications processing uploaded DWG files could be vulnerable

🏢 Internal Only: MEDIUM - Internal users could be targeted via email attachments or shared files

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires crafting malicious DWG file; heap manipulation required for code execution

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: v0.12.5 or later

Vendor Advisory: https://github.com/LibreDWG/libredwg/issues/490

Restart Required: Yes

Instructions:

1. Update LibreDWG to v0.12.5 or later
2. Rebuild any applications using LibreDWG library
3. Restart affected services

🔧 Temporary Workarounds

Disable DWG file processing

all

Temporarily disable LibreDWG-based DWG file processing until patched

Use alternative DWG libraries

all

Switch to alternative DWG processing libraries like Teigha or Open Design Alliance

🧯 If You Can't Patch

Implement strict file upload validation for DWG files
Run LibreDWG processes in sandboxed containers with limited privileges

🔍 How to Verify

Check if Vulnerable:

Check LibreDWG version: redwg --version or examine library version in applications

Check Version:

redwg --version

Verify Fix Applied:

Confirm version is v0.12.5 or later and test with known problematic DWG files

📡 Detection & Monitoring

Log Indicators:

Application crashes when processing DWG files
Memory access violation errors in logs

Network Indicators:

Unusual DWG file uploads to web applications
Multiple failed file processing attempts

SIEM Query:

source="application.log" AND ("segmentation fault" OR "heap corruption" OR "access violation") AND "dwg"

📊 Metadata

CVE ID: CVE-2022-33027

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-416

Published: June 23, 2022

Last Updated: November 21, 2024

🔗 References

https://github.com/LibreDWG/libredwg/issues/490 Exploit,Issue Tracking,Third Party Advisory
https://github.com/LibreDWG/libredwg/issues/490 Exploit,Issue Tracking,Third Party Advisory

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🔗 Related Vulnerabilities

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