CVE-2023-37467 Discourse CSP nonce reuse vulnerability for anonymous users
CSP nonce reuse allows XSS attacks to bypass Content Security Policy protections for anonymous users in Discourse.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-37467?
CVE-2023-37467 is a medium-severity cross-site scripting vulnerability in Discourse Discourse, published on 28 Jul 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Discourse is an open source discussion platform. Prior to version 3.1.0.beta7 of the `beta` and `tests-passed` branches, a CSP (Content Security Policy) nonce reuse vulnerability was discovered could allow cross-site scripting (XSS) attacks to bypass CSP protection for anonymous (i.e. unauthenticated) users. There are no known XSS vectors at the moment, but should one be discovered, this vulnerability would allow the XSS attack to bypass CSP and execute successfully. This vulnerability isn't applicable to logged-in users. Version 3.1.0.beta7 contains a patch. The stable branch doesn't have this vulnerability. A workaround to prevent the vulnerability is to disable Google Tag Manager, i.e., unset the `gtm container id` setting.
Which versions are affected by CVE-2023-37467?
1 open source package ship an affected version, including discourse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
discourse Bitnami | From 1.1.0-beta1 to 1.1.0-beta1 | None |
Products include Discourse Discourse.
How do I fix CVE-2023-37467?
No fix has been published for CVE-2023-37467 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2023-37467 being exploited?
There is no known exploitation of CVE-2023-37467 in the wild and no public exploit code.
Other vulnerabilities in Discourse Discourse
- CVE-2021-41163 RCE via malicious SNS subscription payload
- CVE-2022-36066 Discourse vulnerable to RCE via admins uploading maliciously zipped file
- CVE-2022-39356 Discourse user account takeover via email and invite link
- CVE-2023-22468 Discourse vulnerable to Cross-site Scripting in local oneboxes
- CVE-2026-27934 Discourse leaks private topic title and post excerpt via user action API endpoint
Sources
Also known as BIT-discourse-2023-37467, GHSA-gr5h-hm62-jr3j.