CVE-2024-21641: flarum Open Redirect — Fix

Description

Flarum is open source discussion platform software. Prior to version 1.8.5, the Flarum `/logout` route includes a redirect parameter that allows any third party to redirect users from a (trusted) domain of the Flarum installation to redirect to any link. For logged-in users, the logout must be confirmed. Guests are immediately redirected. This could be used by spammers to redirect to a web address using a trusted domain of a running Flarum installation. The vulnerability has been fixed and published as flarum/core v1.8.5. As a workaround, some extensions modifying the logout route can remedy this issue if their implementation is safe.

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CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Weakness Type (CWE)

CWE-601 CWE-601

Affected Products

Vendor	Product	Versions
flarum	flarum	< 1.8.5

References

Advisories & Patches

https://github.com/flarum/flarum-core/commit/ee8b3b4ad1413a2b0971fdd9e40f812d2a3a9d3a https://github.com/flarum/framework/commit/7d70328471cf3091d92d95c382d277aec7996176 https://github.com/flarum/framework/security/advisories/GHSA-733r-8xcp-w9mr https://github.com/flarum/flarum-core/commit/ee8b3b4ad1413a2b0971fdd9e40f812d2a3a9d3a https://github.com/flarum/framework/commit/7d70328471cf3091d92d95c382d277aec7996176 https://github.com/flarum/framework/security/advisories/GHSA-733r-8xcp-w9mr

Frequently Asked Questions

What is CVE-2024-21641? +

Flarum is open source discussion platform software. Prior to version 1.8.5, the Flarum `/logout` route includes a redirect parameter that allows any third party to redirect users from a (trusted) domain of the Flarum installation to redirect to any link. For logged-in users, the logout must be confirmed. Guests are immediately redirected. This could be used by spammers to redirect to a web address using a trusted domain of a running Flarum installation. The vulnerability has been fixed and published as flarum/core v1.8.5. As a workaround, some extensions modifying the logout route can remedy this issue if their implementation is safe. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2024-21641? +

CVE-2024-21641 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-21641? +

CVE-2024-21641 affects products from flarum, specifically: flarum. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-21641? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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