CVE-2021-4157 : Vulnerability Insights and Analysis
Learn about CVE-2021-4157, a critical vulnerability in the Linux kernel NFS subsystem allowing system crashes or privilege escalation via NFS mirroring exploit.
An out of memory bounds write flaw in the Linux kernel NFS subsystem allows users to crash the system or escalate privileges by exploiting mirroring with NFS.
Understanding CVE-2021-4157
This CVE relates to an out of memory bounds write flaw in the Linux kernel NFS subsystem that could potentially lead to system crashes or privilege escalation.
What is CVE-2021-4157?
The CVE-2021-4157 involves a vulnerability in the Linux kernel NFS subsystem that could allow a user with access to the NFS mount to crash the system or escalate their privileges.
The Impact of CVE-2021-4157
The impact of this vulnerability is significant as it can be exploited by malicious users to disrupt system operations or gain unauthorized access and control over the system.
Technical Details of CVE-2021-4157
This section provides details on the vulnerability description, affected systems, versions, and the exploitation mechanism.
Vulnerability Description
The flaw allows users to trigger an out of memory bounds write (1 or 2 bytes of memory) in the Linux kernel NFS subsystem when using mirroring with NFS.
Affected Systems and Versions
The vulnerability affects systems running kernel version 5.13-rc1 due to the flaw in the NFS subsystem.
Exploitation Mechanism
By exploiting the mirroring feature with NFS, a user can potentially crash the system or escalate privileges by leveraging the out of memory bounds write flaw.
Mitigation and Prevention
To secure systems against CVE-2021-4157, immediate steps and long-term security practices are essential along with patching and updates.
Immediate Steps to Take
It is recommended to restrict access to the NFS mount and closely monitor system activities to detect any unauthorized attempts to exploit the vulnerability.
Long-Term Security Practices
Implementing least privilege access, regular security audits, and keeping systems up to date with the latest patches are crucial for enhancing overall security posture.
Patching and Updates
Applying patches released by the Linux kernel community or respective vendors to address the vulnerability is vital in safeguarding systems from potential exploits.