CVE-2019-19377 : Vulnerability Insights and Analysis

A use-after-free vulnerability in the Linux kernel version 5.0.21 can be exploited by mounting a specially crafted btrfs filesystem image.

Understanding CVE-2019-19377

This CVE involves a use-after-free vulnerability in the btrfs_queue_work function in the Linux kernel version 5.0.21.

What is CVE-2019-19377?

A use-after-free vulnerability can be triggered in the btrfs_queue_work function in fs/btrfs/async-thread.c of the Linux kernel version 5.0.21 by mounting a specifically crafted btrfs filesystem image, conducting certain operations, and subsequently unmounting the image.

The Impact of CVE-2019-19377

Successful exploitation could allow an attacker to execute arbitrary code or cause a denial of service (DoS) condition.
Attackers may gain elevated privileges on the affected system.

Technical Details of CVE-2019-19377

This section provides more technical insights into the vulnerability.

Vulnerability Description

In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing certain operations, and unmounting can lead to a use-after-free vulnerability in btrfs_queue_work in fs/btrfs/async-thread.c.

Affected Systems and Versions

Affected System: Linux kernel version 5.0.21
Affected Component: btrfs_queue_work function in fs/btrfs/async-thread.c
Affected Versions: Not applicable

Exploitation Mechanism

The vulnerability can be exploited by:

Mounting a specially crafted btrfs filesystem image.
Performing specific operations on the mounted image.
Unmounting the image to trigger the use-after-free condition.

Mitigation and Prevention

Protecting systems from CVE-2019-19377 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply security patches provided by the Linux kernel maintainers.
Monitor official sources for updates and advisories regarding this vulnerability.
Restrict access to potentially malicious filesystem images.

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version.
Implement least privilege access controls to limit the impact of potential exploits.
Conduct regular security assessments and audits to identify and mitigate vulnerabilities.

Patching and Updates

Stay informed about security updates and patches released by the Linux kernel maintainers.
Apply patches promptly to ensure the system is protected against known vulnerabilities.