starcitizentools/citizen-skin allows stored XSS in user registration date message
Date: 2025-06
Affected: composer/starcitizentools/citizen-skin
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2025-49575
CVE-2025-49576
CVE-2025-49577
CVE-2025-49578
CVE-2025-49579
CWE: CWE-79
CVSS: 6.5 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N)

### Summary Various date messages returned by `Language::userDate` are inserted into raw HTML, allowing anybody who can edit those messages to insert arbitrary HTML into the DOM. ### Details The result of `$this->lang->userDate( $timestamp, $this->user )` returns unescaped values, but is inserted as raw HTML by Citizen: https://github.com/StarCitizenTools/mediawiki-skins-Citizen/blob/072e4365e9084e4b153eac62d3666566c06f5a49/includes/Components/CitizenComponentUserInfo.php#L55-L60 ### PoC 1. Go to any page using citizen with the uselang parameter set to x-xss and while being logged in Depending on the registration date of the account you're logged in with, various messages can be shown. In my case, it's `november`: ![image](https://github.com/user-attachments/assets/252a3453-99c8-4ce1-b6d6-a8485b7a9a43) ### Impact This impacts wikis where a group has the `editinterface` but not the `editsitejs` user right.


Mitigations:

Architectural layers (MAESTRO):