CVE-2019-19522 : Vulnerability Insights and Analysis

OpenBSD 6.6, in a specific configuration with S/Key or YubiKey authentication enabled, allows local users to gain root access by exploiting their membership in the auth group. This vulnerability arises from the ability of users to overwrite root-owned files in /etc/skey or /var/db/yubikey.

Understanding CVE-2019-19522

In this section, we will delve into the details of CVE-2019-19522.

What is CVE-2019-19522?

CVE-2019-19522 is a security vulnerability in OpenBSD 6.6 that enables local users to escalate their privileges to root by taking advantage of their membership in the auth group and the ability to overwrite root-owned files.

The Impact of CVE-2019-19522

The exploitation of this vulnerability can lead to unauthorized users gaining root access on the affected system, potentially resulting in complete control over the system and sensitive data.

Technical Details of CVE-2019-19522

Let's explore the technical aspects of CVE-2019-19522.

Vulnerability Description

The vulnerability in OpenBSD 6.6 allows local users to elevate their privileges to root by manipulating files in /etc/skey or /var/db/yubikey, even without root ownership requirements.

Affected Systems and Versions

OpenBSD 6.6

Exploitation Mechanism

Local users with membership in the auth group can exploit the vulnerability by overwriting root-owned files in /etc/skey or /var/db/yubikey.

Mitigation and Prevention

Protecting systems from CVE-2019-19522 is crucial. Here are some steps to mitigate the risk and prevent exploitation.

Immediate Steps to Take

Disable S/Key and YubiKey authentication if not essential for system operations.
Regularly monitor and review file permissions in critical directories.
Limit the number of users with membership in the auth group.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access rights.
Conduct regular security audits and vulnerability assessments.
Stay informed about security updates and patches for OpenBSD.

Patching and Updates

Apply patches and updates provided by OpenBSD to address the vulnerability and enhance system security.