CVE-2019-9213 : Security Advisory and Response

In March 2019, a vulnerability was discovered in the Linux kernel prior to version 4.20.14, allowing attackers to exploit kernel NULL pointer dereferences on non-SMAP platforms. This CVE-2019-9213 vulnerability arises due to a missing check for the mmap minimum address in the expand_downwards function.

Understanding CVE-2019-9213

This CVE impacts the Linux kernel before version 4.20.14, potentially leading to security issues on affected systems.

What is CVE-2019-9213?

The absence of a check for the mmap minimum address in the expand_downwards function in mm/mmap.c of the Linux kernel prior to version 4.20.14 creates a vulnerability that can be exploited by attackers to target kernel NULL pointer dereferences on non-SMAP platforms. This vulnerability occurs due to a capability check being performed on the incorrect task.

The Impact of CVE-2019-9213

The vulnerability allows attackers to exploit kernel NULL pointer dereferences on non-SMAP platforms, potentially leading to security breaches and system compromise.

Technical Details of CVE-2019-9213

This section provides more in-depth technical insights into the CVE-2019-9213 vulnerability.

Vulnerability Description

The vulnerability in the Linux kernel before version 4.20.14 arises from the lack of a check for the mmap minimum address in the expand_downwards function, making it easier for attackers to exploit kernel NULL pointer dereferences on non-SMAP platforms.

Affected Systems and Versions

Linux kernel versions before 4.20.14

Exploitation Mechanism

Attackers can exploit this vulnerability by targeting kernel NULL pointer dereferences on non-SMAP platforms due to the missing check for the mmap minimum address.

Mitigation and Prevention

Protecting systems from CVE-2019-9213 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply relevant security patches provided by the Linux kernel maintainers
Monitor for any unusual system behavior that could indicate exploitation of the vulnerability

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version
Implement strong access controls and privilege management to limit potential attack surfaces

Patching and Updates

Ensure timely installation of security patches released by the Linux kernel maintainers to address the CVE-2019-9213 vulnerability.