CVE-2018-12633 : Security Advisory and Response

A vulnerability was found in the Linux kernel that could lead to a local denial of service and information leakage.

Understanding CVE-2018-12633

This CVE identifies a flaw in the Linux kernel that allows a malicious user to trigger severe kernel errors.

What is CVE-2018-12633?

The vulnerability exists in the function vbg_misc_device_ioctl() in the Linux kernel, specifically in the drivers/virt/vboxguest/vboxguest_linux.c file, up to version 4.17.2. It occurs due to a race condition that allows critical variables to be modified, leading to potential denial of service and information leakage.

The Impact of CVE-2018-12633

The exploitation of this vulnerability can result in severe kernel errors, including buffer over-accesses, which can lead to a local denial of service and leakage of information.

Technical Details of CVE-2018-12633

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vbg_misc_device_ioctl() function in the Linux kernel reads the same user data twice, allowing a malicious thread to modify critical variables between the two retrievals, leading to severe kernel errors.

Affected Systems and Versions

Affected System: Linux kernel
Affected Version: Up to 4.17.2

Exploitation Mechanism

The vulnerability arises from a race condition that enables a malicious user to tamper with critical variables in the header of user data, causing severe kernel errors.

Mitigation and Prevention

Protecting systems from CVE-2018-12633 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply relevant patches provided by the Linux kernel maintainers.
Monitor security advisories for updates and apply them promptly.

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version.
Implement proper access controls and monitoring mechanisms to detect and prevent unauthorized access.

Patching and Updates

Regularly check for security updates and patches released by the Linux kernel community.