CVE-2019-15876 Explained : Impact and Mitigation

FreeBSD 12.1-STABLE, 12.1-RELEASE, 11.3-STABLE, and 11.3-RELEASE are affected by a privilege validation issue in the oce network driver, allowing unprivileged users to send commands to device firmware.

Understanding CVE-2019-15876

What is CVE-2019-15876?

Prior to specific versions in FreeBSD, a vulnerability in the oce network driver allowed unprivileged users to send commands to device firmware due to inadequate privilege validation.

The Impact of CVE-2019-15876

The vulnerability could be exploited by unprivileged users to interact with device firmware, potentially leading to unauthorized access or control over the affected systems.

Technical Details of CVE-2019-15876

Vulnerability Description

The issue stemmed from the failure of driver specific ioctl command handlers to verify the privileges of the caller, enabling unprivileged users to send passthrough commands to the device firmware.

Affected Systems and Versions

FreeBSD 12.1-STABLE before r356089
FreeBSD 12.1-RELEASE before 12.1-RELEASE-p3
FreeBSD 11.3-STABLE before r356090
FreeBSD 11.3-RELEASE before 11.3-RELEASE-p7

Exploitation Mechanism

Unprivileged users could exploit this vulnerability to send unauthorized commands to the device firmware, potentially compromising system integrity and security.

Mitigation and Prevention

Immediate Steps to Take

Apply the necessary patches provided by FreeBSD to address the privilege validation issue.
Monitor system logs for any suspicious activities related to unauthorized command interactions.

Long-Term Security Practices

Regularly update FreeBSD systems to the latest stable releases to ensure all security patches are applied.
Implement least privilege access controls to restrict unprivileged users from interacting with critical system components.

Patching and Updates

Ensure timely installation of security updates and patches released by FreeBSD to mitigate the vulnerability and enhance system security.