CVE-2019-20423 : Security Advisory and Response

A vulnerability in the Lustre file system before version 2.12.3 could allow for a buffer overflow and panic due to improper validation of specific packet fields.

Understanding CVE-2019-20423

This CVE relates to a flaw in the ptlrpc module of the Lustre file system that could be exploited by a client to trigger a buffer overflow.

What is CVE-2019-20423?

The vulnerability arises from the failure to adequately validate certain packet fields sent by a client, leading to a buffer overflow and subsequent system panic. The issue specifically occurs in the target_handle_connect() function during the establishment of a connection between a client and a server.

The Impact of CVE-2019-20423

The vulnerability could be exploited by a malicious client to execute arbitrary code or crash the system, potentially leading to a denial of service (DoS) condition.

Technical Details of CVE-2019-20423

The technical aspects of this CVE are as follows:

Vulnerability Description

The vulnerability in the ptlrpc module of the Lustre file system before version 2.12.3 allows for a buffer overflow due to the mishandling of a specific size value during client-server connections.

Affected Systems and Versions

Systems running Lustre file system versions prior to 2.12.3 are vulnerable.

Exploitation Mechanism

Exploitation involves sending crafted packets with specific fields to trigger a buffer overflow in the target_handle_connect() function.

Mitigation and Prevention

To address CVE-2019-20423, consider the following mitigation strategies:

Immediate Steps to Take

Update to Lustre file system version 2.12.3 or later to mitigate the vulnerability.
Monitor network traffic for any suspicious activities that could indicate exploitation attempts.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential attacks.
Regularly review and update security configurations to prevent similar vulnerabilities.

Patching and Updates

Apply patches and updates provided by Lustre to address the vulnerability and enhance system security.