CVE-2021-21900 : What You Need to Know

A code execution vulnerability exists in the dxfRW::processLType() functionality of LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580. An attacker can provide a specially-crafted .dxf file to trigger a use-after-free vulnerability, potentially resulting in high impact levels.

Understanding CVE-2021-21900

This section will cover the details of the CVE-2021-21900 vulnerability, its impact, technical description, affected systems, exploitation mechanism, and mitigation strategies.

What is CVE-2021-21900?

The vulnerability CVE-2021-21900 is a code execution vulnerability present in the dxfRW::processLType() functionality of LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580. By exploiting this vulnerability, an attacker can create a malicious .dxf file that may lead to a use-after-free vulnerability.

The Impact of CVE-2021-21900

The impact of CVE-2021-21900 is rated as high with a CVSS base score of 8.8. This vulnerability can be exploited to execute arbitrary code by providing a specially-crafted file, potentially compromising the confidentiality, integrity, and availability of the affected system.

Technical Details of CVE-2021-21900

In this section, we will delve into the specific technical aspects of CVE-2021-21900, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability stems from a flaw in the LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580 code, allowing attackers to trigger a use-after-free issue through a specially-crafted .dxf file.

Affected Systems and Versions

The affected system is LibreCAD with the specific version being LibreCad libdxfrw 2.2.0-rc2-19-ge02f3580.

Exploitation Mechanism

By enticing a user to open a malicious .dxf file, an attacker can exploit this vulnerability to execute arbitrary code on the targeted system.

Mitigation and Prevention

It is crucial to understand the necessary steps to mitigate the risks associated with CVE-2021-21900 and prevent potential exploitation.

Immediate Steps to Take

Immediately update LibreCad to a patched version that addresses CVE-2021-21900. Exercise caution when opening .dxf files from untrusted sources.

Long-Term Security Practices

Regularly update software and follow security best practices to minimize the risk of code execution vulnerabilities. Consider implementing file parsing safeguards to prevent exploitation.

Patching and Updates

Stay informed about security updates for LibreCad and apply patches promptly to ensure your systems are protected against known vulnerabilities.