XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. XWiki Platform Legacy Old Core and XWiki Platform Old Core versions 1.1 through 16.4.6, 16.5.0-rc-1 through 16.10.4 and 17.0.0-rc-1 through 17.1.0, the XML export of a page in XWiki that can be triggered by any user with view rights on a page by appending ?xpage=xml to the URL includes password and email properties stored on a document that aren't named password or email. This is fixed in versions 16.4.7, 16.10.5 and 17.2.0-rc-1. To work around this issue, the file templates/xml.vm in the deployed WAR can be deleted if the XML isn't needed. There isn't any feature in XWiki itself that depends on the XML export.

XWiki Platform is a generic wiki platform. Prior to 15.10.14, 16.4.6, and 16.10.0-rc-1, protected pages are listed when requesting the REST endpoints /rest/wikis/[wikiName]/pages even if the user doesn't have view rights on them. It's particularly true if the entire wiki is protected with "Prevent unregistered user to view pages": the endpoint would still list the pages of the wiki, though only for the main wiki. The problem has been patched in XWiki 15.10.14, 16.4.6, 16.10.0RC1. In those versions the endpoint can still be requested but the result is filtered out based on pages rights.

XWiki Platform is a generic wiki platform. Prior to 15.10.14, 16.4.6, and 16.10.0-rc-1, it's possible for an user to get access to private information through the REST API - but could also be through another API - when a sub wiki is using "Prevent unregistered users to view pages". The vulnerability only affects subwikis, and it only concerns specific right options such as "Prevent unregistered users to view pages". or "Prevent unregistered users to edit pages". It's possible to detect the vulnerability by enabling "Prevent unregistered users to view pages" and then trying to access a page through the REST API without using any credentials. The vulnerability has been patched in XWiki 15.10.14, 16.4.6 and 16.10.0RC1.

XWiki Platform is a generic wiki platform. The rendered diff in XWiki embeds images to be able to compare the contents and not display a difference for an actually unchanged image. For this, XWiki requests all embedded images on the server side. These requests are also sent for images from other domains and include all cookies that were sent in the original request to ensure that images with restricted view right can be compared. Starting in version 11.10.1 and prior to versions 14.10.15, 15.5.1, and 15.6, this allows an attacker to steal login and session cookies that allow impersonating the current user who views the diff. The attack can be triggered with an image that references the rendered diff, thus making it easy to trigger. Apart from stealing login cookies, this also allows server-side request forgery (the result of any successful request is returned in the image's source) and viewing protected content as once a resource is cached, it is returned for all users. As only successful requests are cached, the cache will be filled by the first user who is allowed to access the resource. This has been patched in XWiki 14.10.15, 15.5.1 and 15.6. The rendered diff now only downloads images from trusted domains. Further, cookies are only sent when the image's domain is the same the requested domain. The cache has been changed to be specific for each user. As a workaround, the image embedding feature can be disabled by deleting `xwiki-platform-diff-xml-<version>.jar` in `WEB-INF/lib/`.

An unauthenticated HTTP GET request to the /client.php endpoint will disclose the default administrator user credentials.