CVE-2019-5596 Explained : Impact and Mitigation

A software flaw in FreeBSD versions 11.2-STABLE, 12.0-STABLE, and 12.0-RELEASE could allow a local user to gain root privileges or escape from a jail environment.

Understanding CVE-2019-5596

This CVE involves a vulnerability in the reference count implementation for UNIX domain sockets in FreeBSD.

What is CVE-2019-5596?

This CVE identifies a bug in FreeBSD versions that could lead to the incorrect release of a file structure, potentially enabling a local user to escalate privileges or escape a restricted environment.

The Impact of CVE-2019-5596

The vulnerability poses a security risk as it could allow a malicious local user to gain root privileges or break out of a jail environment.

Technical Details of CVE-2019-5596

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The bug affects the reference count implementation for UNIX domain sockets, leading to the incorrect release of file structures.

Affected Systems and Versions

FreeBSD 11.2-STABLE (after r338618 and before r343786)
FreeBSD 12.0-STABLE (before r343781)
FreeBSD 12.0-RELEASE (before 12.0-RELEASE-p3)

Exploitation Mechanism

The vulnerability could be exploited by a local user with malicious intent to gain root privileges or escape from a jail environment.

Mitigation and Prevention

To address CVE-2019-5596, consider the following steps:

Immediate Steps to Take

Apply the necessary patches provided by FreeBSD promptly.
Monitor system logs for any suspicious activities.
Restrict access to vulnerable systems.

Long-Term Security Practices

Regularly update and patch FreeBSD systems.
Implement the principle of least privilege to limit user access.
Conduct regular security audits and assessments.

Patching and Updates

Ensure that FreeBSD systems are updated to versions that contain the necessary patches to mitigate the vulnerability.