CVE-2019-20839 : Exploit Details and Defense Strategies

A buffer overflow vulnerability exists in LibVNCServer prior to version 0.9.13, specifically in the libvncclient/sockets.c file. This vulnerability can be exploited by providing a long socket filename.

Understanding CVE-2019-20839

This CVE involves a buffer overflow vulnerability in LibVNCServer.

What is CVE-2019-20839?

CVE-2019-20839 is a buffer overflow vulnerability found in LibVNCServer before version 0.9.13, located in the libvncclient/sockets.c file. The issue arises from providing an excessively long socket filename, leading to a buffer overflow.

The Impact of CVE-2019-20839

The vulnerability allows attackers to execute arbitrary code or crash the application by exploiting the buffer overflow.

Technical Details of CVE-2019-20839

This section covers the technical aspects of the CVE.

Vulnerability Description

The buffer overflow occurs in the libvncclient/sockets.c file of LibVNCServer before version 0.9.13 due to the handling of long socket filenames.

Affected Systems and Versions

Affected Version: LibVNCServer before 0.9.13

Exploitation Mechanism

Attackers can exploit this vulnerability by providing a long socket filename, triggering the buffer overflow.

Mitigation and Prevention

Protecting systems from CVE-2019-20839 is crucial to maintaining security.

Immediate Steps to Take

Update LibVNCServer to version 0.9.13 or later to mitigate the vulnerability.
Implement network security measures to restrict access to vulnerable services.

Long-Term Security Practices

Regularly update software and libraries to patch known vulnerabilities.
Conduct security assessments and penetration testing to identify and address potential weaknesses.

Patching and Updates

Stay informed about security advisories and updates from LibVNCServer and related vendors to apply patches promptly.