CVE-2022-23549 Discourse vulnerable to bypass of post max_length using HTML comments

What is CVE-2022-23549?

CVE-2022-23549 is a medium-severity vulnerability in Discourse Discourse, published on 5 Jan 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Discourse is an option source discussion platform. Prior to version 2.8.14 on the `stable` branch and version 2.9.0.beta16 on the `beta` and `tests-passed` branches, users can create posts with raw body longer than the `max_length` site setting by including html comments that are not counted toward the character limit. This issue is patched in versions 2.8.14 and 2.9.0.beta16. There are no known workarounds.

Weakness: CWE-20

Which versions are affected by CVE-2022-23549?

1 open source package ship an affected version, including discourse. It affects 1 product.

Products include Discourse Discourse.

How do I fix CVE-2022-23549?

Upgrade discourse to 2.8.14 or later.

Is CVE-2022-23549 being exploited?

There is no known exploitation of CVE-2022-23549 in the wild and no public exploit code.

Other vulnerabilities in Discourse Discourse

• CVE-2021-41163 RCE via malicious SNS subscription payload Critical 10.0
• CVE-2022-36066 Discourse vulnerable to RCE via admins uploading maliciously zipped file Critical 9.1
• CVE-2022-39356 Discourse user account takeover via email and invite link High 8.9
• CVE-2023-22468 Discourse vulnerable to Cross-site Scripting in local oneboxes High 8.8
• CVE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint High 8.7

All Discourse Discourse vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-discourse-2022-23549, GHSA-p47g-v5wr-p4xp.