CVE-2017-5546 Explained : Impact and Mitigation

In the Linux kernel versions 4.8.x and 4.9.x before 4.9.5, a vulnerability exists in the freelist-randomization feature in the mm/slab.c module. This flaw can be exploited by local users to create duplicate freelist entries, potentially leading to a denial of service or other impacts.

Understanding CVE-2017-5546

This CVE involves a specific feature in the Linux kernel that can be manipulated under certain conditions to cause system instability.

What is CVE-2017-5546?

The freelist-randomization feature in the Linux kernel versions 4.8.x and 4.9.x before 4.9.5 allows local users to disrupt system operations by generating duplicate freelist entries, potentially resulting in a denial of service or other adverse effects.

The Impact of CVE-2017-5546

Exploitation of this vulnerability can lead to a denial of service condition or other unspecified impacts, particularly when a large random number is selected in certain scenarios.

Technical Details of CVE-2017-5546

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The flaw in the freelist-randomization feature in mm/slab.c in the Linux kernel versions 4.8.x and 4.9.x before 4.9.5 enables local users to trigger duplicate freelist entries, potentially causing a system crash or other adverse effects.

Affected Systems and Versions

Linux kernel versions 4.8.x and 4.9.x before 4.9.5

Exploitation Mechanism

The vulnerability can be exploited by local users under specific conditions, particularly when a large random number is chosen in certain opportunistic scenarios.

Mitigation and Prevention

Protecting systems from CVE-2017-5546 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply relevant patches and updates provided by the Linux kernel maintainers
Monitor for any unusual system behavior that could indicate exploitation

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version
Implement least privilege access controls to limit the impact of potential vulnerabilities

Patching and Updates

Ensure timely installation of security patches released by the Linux kernel maintainers to address the freelist-randomization vulnerability