CVE-2019-19520 : What You Need to Know

In OpenBSD 6.6, an issue exists with xlock where local users can obtain auth group privileges by supplying a LIBGL_DRIVERS_PATH environment variable. This vulnerability arises from mishandling of dlopen in the xenocara/lib/mesa/src/loader/loader.c file.

Understanding CVE-2019-19520

This CVE involves a privilege escalation vulnerability in OpenBSD 6.6 through the xlock application.

What is CVE-2019-19520?

The vulnerability allows local users to gain the privileges of the auth group by manipulating the LIBGL_DRIVERS_PATH environment variable.

The Impact of CVE-2019-19520

The exploitation of this vulnerability could lead to unauthorized access and privilege escalation for local users on affected systems.

Technical Details of CVE-2019-19520

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vulnerability in xlock in OpenBSD 6.6 allows local users to gain auth group privileges by providing a specific environment variable, due to mishandling of dlopen in the loader.c file.

Affected Systems and Versions

Systems running OpenBSD 6.6
Specifically, the xlock application

Exploitation Mechanism

Local users can exploit the vulnerability by manipulating the LIBGL_DRIVERS_PATH environment variable

Mitigation and Prevention

Protecting systems from CVE-2019-19520 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply the necessary patches provided by OpenBSD promptly
Monitor and restrict the environment variables that can be manipulated by users

Long-Term Security Practices

Implement the principle of least privilege to restrict user access
Regularly update and patch systems to address known vulnerabilities

Patching and Updates

Stay informed about security advisories from OpenBSD and apply patches as soon as they are released