CVE-2020-8428 : Security Advisory and Response

Linux kernel before 5.5 has a use-after-free vulnerability in fs/namei.c, allowing local users to cause a denial of service or potentially access sensitive kernel memory.

Understanding CVE-2020-8428

This CVE involves a vulnerability in the Linux kernel that can be exploited by local users to disrupt system operations or gain unauthorized access to kernel memory.

What is CVE-2020-8428?

The vulnerability exists in fs/namei.c in the Linux kernel before version 5.5
It involves a use-after-free issue that can lead to a denial of service (OOPS) or potential leakage of sensitive information from kernel memory
Identified as CID-d0cb50185ae9
One possible attack scenario involves manipulating a UNIX domain socket during a directory change

The Impact of CVE-2020-8428

Local users can exploit this vulnerability to disrupt system functionality or extract sensitive data from kernel memory
Attackers may trigger a denial of service condition or potentially access confidential information

Technical Details of CVE-2020-8428

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in fs/namei.c in the Linux kernel before 5.5 allows for a may_create_in_sticky use-after-free
This flaw enables local users to trigger a denial of service or potentially retrieve sensitive data from kernel memory

Affected Systems and Versions

Linux kernel versions before 5.5 are impacted by this vulnerability
Local users with access to the system can potentially exploit this issue

Exploitation Mechanism

Attackers can exploit the vulnerability by manipulating a UNIX domain socket during a directory change

Mitigation and Prevention

Protecting systems from CVE-2020-8428 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply relevant security patches provided by the Linux kernel maintainers
Monitor system logs for any suspicious activities that might indicate exploitation
Restrict access to vulnerable systems to authorized personnel only

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version to mitigate known vulnerabilities
Implement the principle of least privilege to limit user access and reduce the attack surface

Patching and Updates

Stay informed about security advisories from Linux distributions and apply patches promptly to address vulnerabilities