CVE-2023-23935 Presence of restricted personal Discourse messages may be leaked if tagged with a tag
Attackers can infer the existence of private messages by polling tag counts, leaking sensitive metadata about user communications.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2023-23935?
CVE-2023-23935 is a low-severity vulnerability in Discourse Discourse, published on 16 Mar 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 open-source messaging platform. In versions 3.0.1 and prior on the `stable` branch and versions 3.1.0.beta2 and prior on the `beta` and `tests-passed` branches, the count of personal messages displayed for a tag is a count of all personal messages regardless of whether the personal message is visible to a given user. As a result, any users can technically poll a sensitive tag to determine if a new personal message is created even if the user does not have access to the personal message.
In the patched versions, the count of personal messages tagged with a given tag is hidden by default. To revert to the old behaviour of displaying the count of personal messages for a given tag, an admin may enable the `display_personal_messages_tag_counts` site setting.
Weakness: CWE-200
Which versions are affected by CVE-2023-23935?
1 open source package ship an affected version, including discourse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
discourse Bitnami | All versions | 3.0.1 |
Products include Discourse Discourse.
How do I fix CVE-2023-23935?
Upgrade discourse to 3.0.1 or later.
Is CVE-2023-23935 being exploited?
There is no known exploitation of CVE-2023-23935 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-2023-23935, GHSA-rf8j-mf8c-82v7.