CVE-2023-40176: SXSS in the user profile via the timezone displayer

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 80.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-08-23 · updated 2026-06-17
Weakness: CWE-79

Description

XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any registered user can exploit a stored XSS through their user profile by setting the payload as the value of the time zone user preference. Even though the time zone is selected from a drop down (no free text value) it can still be set from JavaScript (using the browser developer tools) or by calling the save URL on the user profile with the right query string. Once the time zone is set it is displayed without escaping which means the payload gets executed for any user that visits the malicious user profile, allowing the attacker to steal information and even gain more access rights (escalation to programming rights). This issue is present since version 4.1M2 when the time zone user preference was introduced. The issue has been fixed in XWiki 14.10.5 and 15.1RC1.

Affected products

xwiki-platform: from 4.1.1 before 14.10.5; 4.1-milestone2, 15.0, 15.0-rc1 — fixed in 14.10.5

How to fix

Upgrade to a fixed version: xwiki-platform 14.10.5. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2023-40176 or the next vulnerability affects your stack