CVE-2023-28356 Explained : Impact and Mitigation

A vulnerability has been identified in Rocket.Chat that can lead to a denial of service condition when a specific chain of characters is included in a chat message. This can result in the affected process entering a hot loop, consuming excessive CPU resources (~120%) and causing the service to become unresponsive.

Understanding CVE-2023-28356

This section will delve into the details of CVE-2023-28356, shedding light on what it entails and its potential impact.

What is CVE-2023-28356?

CVE-2023-28356 is a vulnerability in Rocket.Chat that allows for a denial of service attack through the exploitation of a specific character chain within chat messages. This flaw can trigger a hot loop scenario in one of the processes, leading to high CPU consumption and unresponsiveness of the service.

The Impact of CVE-2023-28356

The impact of this vulnerability is significant as it can disrupt the normal operations of Rocket.Chat services, rendering them unresponsive and potentially causing downtime for users. The excessive CPU consumption can also impact the overall performance of the system.

Technical Details of CVE-2023-28356

In this section, we will explore the technical aspects of CVE-2023-28356, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability in Rocket.Chat arises from a flaw that allows an attacker to craft a message with a specific chain of characters, triggering a hot loop within one of the processes. This leads to a denial of service condition by consuming excessive CPU resources.

Affected Systems and Versions

The affected system by CVE-2023-28356 is Rocket.Chat, specifically versions prior to 6.0. However, it is important to note that this issue has been addressed in version 6.0 and backported for supported versions. Users are advised to upgrade to the patched version to mitigate the vulnerability.

Exploitation Mechanism

The exploitation of CVE-2023-28356 involves sending a maliciously crafted message containing the specific chain of characters to the affected chat service. Once the message is received and processed, it triggers the hot loop scenario, leading to the denial of service condition.

Mitigation and Prevention

To safeguard systems against CVE-2023-28356 and prevent potential exploitation, certain mitigation and prevention measures can be implemented.

Immediate Steps to Take

Users should update their Rocket.Chat installations to version 6.0 or later, where the vulnerability has been addressed.
It is advisable to monitor CPU usage and system performance for any unusual spikes that could indicate a denial of service attack.

Long-Term Security Practices

Regularly updating software and systems is crucial to ensuring that known vulnerabilities are patched promptly.
Implementing network and application-level monitoring can help in detecting and mitigating potential denial of service attacks.

Patching and Updates

Users of Rocket.Chat are encouraged to keep abreast of security advisories and promptly apply patches and updates released by the vendor. Regularly checking for and applying security updates is essential in ensuring the security and integrity of the chat service.