CVE-2023-27294 Cross-site scripting in OpenCATS

Medium 5.4 Published 28 Feb 2023 Updated 21 Mar 2025

Authenticated attackers can inject malicious JavaScript into calendar event descriptions, leading to session theft or forced actions for other users.

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: None listed

What is CVE-2023-27294?

CVE-2023-27294 is a medium-severity cross-site scripting vulnerability in OpenCATS, published on 28 Feb 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

Improper neutralization of input during web page generation allows an authenticated attacker with access to a restricted account to submit malicious Javascript as the description for a calendar event, which would then be executed in other users' browsers if they browse to that event. This could result in stealing session tokens from users with higher permission levels or forcing users to make actions without their knowledge.

Weakness: CWE-79

Which versions are affected by CVE-2023-27294?

It affects 1 product.

Products include Opencats Opencats.

How do I fix CVE-2023-27294?

No fix has been published for CVE-2023-27294 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-2023-27294 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-27294 exists.

Sources

Also known as GHSA-85f4-cmhq-rx89.