CVE-2021-43792 : Vulnerability Insights and Analysis

Discourse is an open-source discussion platform that has been affected by a vulnerability that could lead to notifications leakage and exposure of sensitive information to unauthorized users.

Understanding CVE-2021-43792

What is CVE-2021-43792?

Discourse, a platform that allows tag groups with restricted visibility, had a flaw where users could still receive notifications related to tags after their access was revoked.

The Impact of CVE-2021-43792

The vulnerability could result in users receiving notifications for tags they should no longer have access to, potentially exposing sensitive information to unauthorized parties.

Technical Details of CVE-2021-43792

Vulnerability Description

The issue affected users using the "Tags are visible only to the following groups" feature in Discourse. Users could still receive tag-related notifications even after losing access to the specific tag.

Affected Systems and Versions

Product: Discourse
Vendor: Discourse
Affected Versions:
Stable < 2.7.11
Beta < 2.8.0.beta9
Tests-passed < 2.8.0.beta9

Exploitation Mechanism

The vulnerability allowed users to receive notifications for tags they lost access to due to the way tag groups were implemented in the affected versions of Discourse.

Mitigation and Prevention

Immediate Steps to Take

Upgrade Discourse to version 2.7.11 or later to patch the vulnerability.
Review and adjust tag group permissions to ensure sensitive information is not exposed.

Long-Term Security Practices

Regularly update Discourse and other software to the latest versions to prevent known vulnerabilities.
Educate users on best practices for managing tags and notifications.

Patching and Updates

Ensure timely application of updates and patches provided by Discourse to address security issues.