CVE-2018-18690 : What You Need to Know

CVE-2018-18690 was published on October 26, 2018, and affects the Linux kernel prior to version 4.17. This vulnerability allows a local attacker to render an xfs filesystem inoperative by exploiting an unchecked error condition during an xfs attribute change.

Understanding CVE-2018-18690

This CVE entry highlights a specific vulnerability in the Linux kernel that could lead to filesystem issues when manipulated by a local attacker.

What is CVE-2018-18690?

Prior to version 4.17 of the Linux kernel, an attacker with local access could potentially disrupt the functionality of an xfs filesystem by triggering an unchecked error condition during an xfs attribute change.

The Impact of CVE-2018-18690

The vulnerability could allow an attacker to make the xfs filesystem non-operational until the next mount by mishandling ATTR_REPLACE operations during the conversion of an attribute from short to long form.

Technical Details of CVE-2018-18690

This section delves into the technical aspects of the CVE, including the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The issue arises from the mishandling of ATTR_REPLACE operations during the conversion of an attribute from short to long form in the xfs_attr_shortform_addname function located in fs/xfs/libxfs/xfs_attr.c.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: Not applicable

Exploitation Mechanism

An individual with local access and the ability to modify attributes on an xfs filesystem could exploit this vulnerability to disrupt the filesystem's operation.

Mitigation and Prevention

In this section, we outline the steps to mitigate the CVE-2018-18690 vulnerability.

Immediate Steps to Take

Update to a version of the Linux kernel equal to or later than 4.17 to address the vulnerability.
Monitor vendor advisories and apply patches promptly.

Long-Term Security Practices

Implement the principle of least privilege to restrict access to critical systems.
Regularly review and update security configurations to prevent similar vulnerabilities.

Patching and Updates

Stay informed about security updates for the Linux kernel and apply them as soon as they are available.