CVE-2021-3178 : Security Advisory and Response
Learn about CVE-2021-3178, a Linux kernel vulnerability allowing remote attackers to traverse file systems via NFS exports. Find out impact, affected versions, and mitigation steps.
A detailed overview of CVE-2021-3178 highlighting the vulnerability, impact, technical details, and mitigation strategies.
Understanding CVE-2021-3178
This section delves into the specifics of the CVE-2021-3178 vulnerability.
What is CVE-2021-3178?
The CVE-2021-3178 vulnerability exists in fs/nfsd/nfs3xdr.c in the Linux kernel through version 5.10.8. It allows remote attackers to traverse to other parts of the filesystem via READDIRPLUS, particularly when there is an NFS export of a subdirectory of a filesystem.
The Impact of CVE-2021-3178
The vulnerability could be exploited by remote attackers to navigate through the filesystem, potentially accessing unauthorized parts and compromising system integrity. It raises concerns about the security of NFS exports and the potential for unauthorized access.
Technical Details of CVE-2021-3178
This section explores the technical aspects of CVE-2021-3178.
Vulnerability Description
The vulnerability in fs/nfsd/nfs3xdr.c allows attackers to bypass filesystem restrictions and access unintended parts of the filesystem through READDIRPLUS.
Affected Systems and Versions
The vulnerability affects the Linux kernel versions up to 5.10.8 where NFS exports of subdirectories are present.
Exploitation Mechanism
Remote attackers can exploit this vulnerability by leveraging the READDIRPLUS function to navigate through the filesystem, potentially gaining unauthorized access.
Mitigation and Prevention
This section provides guidance on mitigating the CVE-2021-3178 vulnerability.
Immediate Steps to Take
System administrators should apply relevant patches promptly and monitor for any signs of unauthorized access or suspicious activities.
Long-Term Security Practices
Implementing robust access controls, regular security audits, and staying updated on security advisories are essential for long-term security.
Patching and Updates
Regularly update the Linux kernel to versions beyond 5.10.8 to mitigate the vulnerability and enhance system security.