CVE-2021-21899 : Exploit Details and Defense Strategies

A code execution vulnerability exists in the dwgCompressor::copyCompBytes21 functionality of LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580. A specially-crafted .dwg file can lead to a heap buffer overflow, allowing an attacker to trigger this vulnerability.

Understanding CVE-2021-21899

This section will provide insights into the details and impact of CVE-2021-21899.

What is CVE-2021-21899?

CVE-2021-21899 is a code execution vulnerability in LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580, where a malicious .dwg file can trigger a heap buffer overflow.

The Impact of CVE-2021-21899

This vulnerability has a CVSS base score of 8.8, indicating a high severity level with significant impacts on confidentiality, integrity, and availability of affected systems.

Technical Details of CVE-2021-21899

In this section, the technical aspects of the vulnerability will be discussed.

Vulnerability Description

The vulnerability arises from improper restriction of operations within the bounds of a memory buffer, categorized under CWE-119.

Affected Systems and Versions

Product affected: LibreCAD Version affected: LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580

Exploitation Mechanism

An attacker can exploit this vulnerability by providing a specially-crafted .dwg file to trigger a heap buffer overflow.

Mitigation and Prevention

This section will outline steps to mitigate and prevent exploitation of CVE-2021-21899.

Immediate Steps to Take

Users should apply security updates provided by the vendor and exercise caution when handling .dwg files in LibreCAD.

Long-Term Security Practices

Regularly updating software, implementing strong access controls, and conducting security audits can enhance overall system security.

Patching and Updates

Ensure timely installation of patches and updates released by LibreCAD to address the vulnerability.