CVE-2021-43850 : What You Need to Know

Discourse is an open source platform for community discussion. In affected versions, admins users can trigger a Denial of Service attack via the

/message-bus/_diagnostics

path. The impact of this vulnerability is significant on multisite Discourse instances, where any admin user on any of the forums can exploit the

/message-bus/_diagnostics

path. The vulnerability has been patched, and users are advised to upgrade to version 2.8.0.beta10 or 2.7.12. No workarounds are available.

Understanding CVE-2021-43850

This CVE describes a Denial of Service vulnerability in Discourse.

What is CVE-2021-43850?

CVE-2021-43850 highlights an issue in Discourse that allows admin users to conduct a Denial of Service attack via a specific path.

The Impact of CVE-2021-43850

The vulnerability presents a medium-severity risk with high availability impact on multisite Discourse instances.

Technical Details of CVE-2021-43850

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability allows admin users to trigger a Denial of Service attack via the

/message-bus/_diagnostics

path.

Affected Systems and Versions

Product: Discourse
Vendor: Discourse
Affected Versions:
< 2.7.12

= 2.8.0.beta, < 2.8.0.beta10

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Scope: Changed
Availability Impact: High
CVSS Base Score: 6.8
Integrity Impact: None
Confidentiality Impact: None

Mitigation and Prevention

Guidelines to address and prevent exploitation of the vulnerability.

Immediate Steps to Take

Upgrade to version 2.8.0.beta10 or 2.7.12 to mitigate the vulnerability.

Long-Term Security Practices

Regularly update and patch Discourse installations.
Implement access controls to limit exposure to vulnerable paths.

Patching and Updates

The problem has been patched. Ensure timely installation of updates to stay protected.