CVE-2018-1000028 : Security Advisory and Response

A security flaw related to Incorrect Access Control has been identified in the Linux kernel versions 4.15-rc4 and higher, 4.14.8 and higher, 4.9.76 and higher, and 4.4.111 and higher, following the commit bdcf0a423ea1. This vulnerability affects the NFS server (nfsd) and may allow remote users to gain unauthorized access to read or write files via NFS. Exploiting this vulnerability requires the NFS server to have the "rootsquash" options enabled when exporting a filesystem. However, this issue has been addressed in a subsequent commit, 1995266727fa.

Understanding CVE-2018-1000028

A security vulnerability in the Linux kernel affecting NFS server (nfsd) versions 4.15-rc4 and higher.

What is CVE-2018-1000028?

The CVE-2018-1000028 vulnerability is related to Incorrect Access Control in the Linux kernel, allowing unauthorized remote access via NFS.

The Impact of CVE-2018-1000028

This vulnerability could enable remote users to read or write files they are not authorized to access through NFS.

Technical Details of CVE-2018-1000028

The technical aspects of the CVE-2018-1000028 vulnerability.

Vulnerability Description

The vulnerability exists in Linux kernel versions 4.15-rc4 and higher, affecting the NFS server (nfsd).
Exploiting the flaw requires the NFS server to have the "rootsquash" options enabled.

Affected Systems and Versions

Linux kernel versions 4.15-rc4 and higher
Linux kernel versions 4.14.8 and higher
Linux kernel versions 4.9.76 and higher
Linux kernel versions 4.4.111 and higher

Exploitation Mechanism

Remote users can exploit the vulnerability to gain unauthorized access via NFS.
The NFS server must have the "rootsquash" options enabled when exporting a filesystem.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2018-1000028 vulnerability.

Immediate Steps to Take

Disable the "rootsquash" option on the NFS server if not required.
Apply patches provided by the Linux kernel to address the vulnerability.

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version.
Implement proper access controls and monitoring on NFS servers.

Patching and Updates

Ensure timely installation of security patches released by the Linux kernel maintainers.