Flarum, the popular open source discussion platform, has recently been found to have a serious security vulnerability. This consequence of this flaw in Flarum's page title system is a potential cross-site scripting (XSS) attack, potentially affecting all communities running Flarum from version v1.5. to v1.6.1. The issue, assigned CVE-2022-41938, has been resolved in the recently released Flarum/core v1.6.2, and affected communities are advised to upgrade as soon as possible.

The Vulnerability

Flarum's page title system was changed after version v1.5, allowing for page titles to be converted into HTML DOM nodes when pages were rendered, which went unnoticed. This introduced a new vulnerability by enabling an attacker to inject malicious HTML markup using a discussion title input, either when creating a new discussion or renaming an existing one.

The exploit only happens after a visitor opens the impacted discussion page, thus executing the malicious HTML markup. This XSS vulnerability affects all Flarum instances running from version v1.5. to v1.6.1.

Here's an example of how an attacker could use the vulnerability to inject malicious HTML code

<script>alert("XSS Attack!");</script>

While the above example is relatively harmless, sophisticated attackers could use this exploit to steal sensitive data such as user credentials or perform other malicious activities.

The Solution

The Flarum team has been quick to respond to this vulnerability. The fix is published with Flarum/core v1.6.2, which should now be available to all Flarum users. It is strongly recommended to upgrade your Flarum instance to v1.6.2 as soon as possible if you are running any version between v1.5. and v1.6.1.

You can find the official release notes for Flarum/core v1.6.2 here, which provides details about the changes and the patch applied to address this issue.

In case you need assistance on upgrading your Flarum community, refer to their documentation.

No Known Workarounds

Unfortunately, there are no known workarounds for CVE-2022-41938. The only way to protect your Flarum discussion platform against this XSS vulnerability is by upgrading to Flarum/core v1.6.2.

Conclusion

It is crucial to be vigilant about possible vulnerabilities in widely-used open source platforms like Flarum. By quickly addressing and providing a patch for CVE-2022-41938, the Flarum team has demonstrated commitment to security and reliability. Communities using Flarum should promptly upgrade to the v1.6.2 version to ensure the security of their users.

Timeline

Published on: 11/19/2022 01:15:00 UTC
Last modified on: 11/26/2022 03:19:00 UTC