Headline
CVE-2023-37277: No CSRF protection on REST API
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. The REST API allows executing all actions via POST requests and accepts text/plain, multipart/form-data or application/www-form-urlencoded as content types which can be sent via regular HTML forms, thus allowing cross-site request forgery. With the interaction of a user with programming rights, this allows remote code execution through script macros and thus impacts the integrity, availability and confidentiality of the whole XWiki installation. For regular cookie-based authentication, the vulnerability is mitigated by SameSite cookie restrictions but as of March 2023, these are not enabled by default in Firefox and Safari. The vulnerability has been patched in XWiki 14.10.8 and 15.2 by requiring a CSRF token header for certain request types that are susceptible to CSRF attacks.
XWiki REST API relies on the session cookie to authenticate and it currently does not perform any kind of check to prevent a CSRF attack.
So it’s possible to create a POST request from another website that might change the data.
For example, I might create a fake poll that when submitted by an XWiki.org admin will grant me admin rights by performing a POST request.
Related news
### Impact The REST API allows executing all actions via POST requests and accepts `text/plain`, `multipart/form-data` or `application/www-form-urlencoded` as content types which can be sent via regular HTML forms, thus allowing cross-site request forgery. With the interaction of a user with programming rights, this allows remote code execution through script macros and thus impacts the integrity, availability and confidentiality of the whole XWiki installation. For regular cookie-based authentication, the vulnerability is mitigated by SameSite cookie restrictions but as of March 2023, these are not enabled by default in Firefox and Safari. ### Patches The vulnerability has been patched in XWiki 14.10.8 and 15.2 by requiring a CSRF token header for certain request types that are susceptible to CSRF attacks. ### Workarounds It is possible to check for the `Origin` header in a reverse proxy to protect the REST endpoint from CSRF attacks, see [the Jira issue](https://jira.xwiki.org/b...