CVE-2018-12896 Explained : Impact and Mitigation

A vulnerability was detected in the Linux kernel up to version 4.17.3, involving an Integer Overflow in the POSIX timer code. This flaw allows for unpredictable values in overrun accounting, leading to a denial of service through specific system calls.

Understanding CVE-2018-12896

This CVE identifies a critical vulnerability in the Linux kernel that can be exploited by local attackers to cause a denial of service.

What is CVE-2018-12896?

The vulnerability in the Linux kernel up to version 4.17.3 is caused by an Integer Overflow in the POSIX timer code. This issue arises due to inconsistencies in overrun accounting, potentially allowing for manipulation by attackers with local access.

The Impact of CVE-2018-12896

The vulnerability can be exploited by attackers to trigger a denial of service condition on affected systems. By carefully crafting specific system calls, malicious actors can exploit the Integer Overflow to disrupt system functionality.

Technical Details of CVE-2018-12896

This section provides detailed technical insights into the CVE-2018-12896 vulnerability.

Vulnerability Description

The Integer Overflow in kernel/time/posix-timers.c results in unpredictable overrun accounting values, accessible to user space through certain system calls, enabling attackers to manipulate the values and cause a denial of service.

Affected Systems and Versions

Affected systems: Linux kernel up to version 4.17.3
Affected components: POSIX timer code

Exploitation Mechanism

The vulnerability can be exploited by local attackers through carefully crafted mmap, futex, timer_create, and timer_settime system calls, leveraging the Integer Overflow in overrun accounting to disrupt system operations.

Mitigation and Prevention

Protecting systems from CVE-2018-12896 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by the Linux kernel maintainers promptly to mitigate the vulnerability.
Monitor system logs for any suspicious activities that could indicate exploitation attempts.

Long-Term Security Practices

Implement the principle of least privilege to restrict user access and minimize the impact of potential attacks.
Regularly update and patch the Linux kernel and associated components to address security vulnerabilities.

Patching and Updates

Stay informed about security advisories and updates released by the Linux kernel community to address CVE-2018-12896.
Ensure timely application of patches to maintain a secure system environment.