CVE-2019-18885 : What You Need to Know

A vulnerability was identified in fs/btrfs/volumes.c within the Linux kernel prior to version 5.1. This vulnerability involves a NULL pointer dereference that can be triggered by a manipulated btrfs image. The mishandling of fs_devices->devices within the find_device function leads to this vulnerability. It is alternatively referred to as CID-09ba3bc9dd15.

Understanding CVE-2019-18885

This CVE pertains to a vulnerability in the Linux kernel that allows for a NULL pointer dereference through a crafted btrfs image.

What is CVE-2019-18885?

CVE-2019-18885 is a vulnerability in the Linux kernel that can be exploited via a manipulated btrfs image, leading to a NULL pointer dereference in the fs/btrfs/volumes.c file.

The Impact of CVE-2019-18885

This vulnerability can be exploited by an attacker to cause a denial of service (DoS) or potentially execute arbitrary code on the affected system, compromising its integrity and availability.

Technical Details of CVE-2019-18885

This section provides more in-depth technical details about the CVE.

Vulnerability Description

The vulnerability in fs/btrfs/volumes.c in the Linux kernel before version 5.1 allows for a btrfs_verify_dev_extents NULL pointer dereference via a crafted btrfs image due to mishandling of fs_devices->devices within find_device, also known as CID-09ba3bc9dd15.

Affected Systems and Versions

Affected System: Linux kernel before version 5.1
Affected Component: fs/btrfs/volumes.c

Exploitation Mechanism

The vulnerability can be exploited by manipulating a btrfs image to trigger a NULL pointer dereference in the find_device function, leading to the exploitation of the mishandled fs_devices->devices.

Mitigation and Prevention

Protecting systems from CVE-2019-18885 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update the Linux kernel to version 5.1 or newer to mitigate the vulnerability.
Monitor vendor advisories and apply patches promptly.

Long-Term Security Practices

Regularly update and patch the Linux kernel and associated components.
Implement security best practices to prevent unauthorized access and exploitation.

Patching and Updates

Apply patches provided by the Linux kernel maintainers to address the vulnerability.