XWiki Cross-Site Request Forgery (CSRF) Vulnerability - CVE-2021-32732

Impact It39s possible to know if a user has or not an account in a wiki related to an email address and which username(s) is actually tied to that email by forging a request to the Forgot username page. Note that since this page does not have a CSRF check it39s quite easy to perform a lot of those requests. Patches This issue has been patched in XWiki 12.10.5 and 13.2RC1. Two different patches are provided: - a first one to fix the CSRF problem - a more complex one that now relies on sending an email for the Forgot username process. Workarounds It39s possible to fix the problem without uprading by editing the ForgotUsername page in version below 13.x to use the following code: https://github.com/xwiki/xwiki-platform/blob/69548c0320cbd772540cf4668743e69f879812cf/xwiki-platform-core/xwiki-platform-administration/xwiki-platform-administration-ui/src/main/resources/XWiki/ForgotUsername.xmlL39-L123 In version after 13.x it39s also possible to edit manually the forgotusername.vm file but it39s really encouraged to upgrade the version here. References https://jira.xwiki.org/browse/XWIKI-18384 https://jira.xwiki.org/browse/XWIKI-18408 For more information If you have any questions or comments about this advisory: Open an issue in Jira XWiki(https://jira.xwiki.org) Email us at security ML(mailto:securityxwiki.org)