CVE-2019-20054 : Exploit Details and Defense Strategies

The drop_sysctl_table() function in fs/proc/proc_sysctl.c in the Linux kernel prior to version 5.0.6 exhibits a NULL pointer dereference issue, also known as CID-23da9588037e.

Understanding CVE-2019-20054

This CVE involves a vulnerability in the Linux kernel that can lead to a NULL pointer dereference issue.

What is CVE-2019-20054?

CVE-2019-20054 is a vulnerability in the Linux kernel before version 5.0.6, specifically in the drop_sysctl_table() function in fs/proc/proc_sysctl.c. The issue is related to put_links and is identified as CID-23da9588037e.

The Impact of CVE-2019-20054

This vulnerability can be exploited to cause a NULL pointer dereference, potentially leading to a denial of service (DoS) condition or other impacts on affected systems.

Technical Details of CVE-2019-20054

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability in drop_sysctl_table() in fs/proc/proc_sysctl.c before Linux kernel version 5.0.6 results in a NULL pointer dereference, specifically related to put_links.

Affected Systems and Versions

Affected systems: Linux kernel versions before 5.0.6
Affected component: drop_sysctl_table() function in fs/proc/proc_sysctl.c

Exploitation Mechanism

The vulnerability can be exploited by triggering the NULL pointer dereference issue in the affected function, potentially leading to system instability or crashes.

Mitigation and Prevention

To address CVE-2019-20054, follow these mitigation strategies:

Immediate Steps to Take

Apply patches provided by the Linux kernel maintainers.
Monitor official sources for updates and security advisories.

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version.
Implement proper access controls and security measures to reduce the risk of exploitation.

Patching and Updates

Update to Linux kernel version 5.0.6 or later to mitigate the vulnerability.