XWiki Platform vulnerable to privilege escalation (PR) from account through TipsPanel
### Impact
It's possible to execute any wiki content with the right of the TipsPanel author by creating a tip UI extension.
To reproduce:
* Add an object of type UIExtensionClass
* Set "Extension Point ID" to org.xwiki.platform.help.tipsPanel
* Set "Extension ID" to org.xwiki.platform.user.test (needs to be unique but otherwise doesn't matter)
* Set "Extension Parameters" to
```
tip={{async async="true" cached="false" context="doc.reference"}}{{groovy}}println("Hello " + "from groovy!"){{/groovy}}{{/async}}
```
* Set "Extension Scope" to "Current User".
* Click "Save & View"
* Open the "Help.TipsPanel" document at <xwiki-host>/xwiki/bin/view/Help/TipsPanel where <xwiki-host> is the URL of your XWiki installation and press refresh repeatedly.
The groovy macro is executed, after the fix you get an error instead.
### Patches
This has been patched in XWiki 15.1-rc-1 and 14.10.5.
### Workarounds
There are no known workarounds for it.
### References
*
https://jira.xwiki.org/browse/XWIKI-20281
*
https://github.com/xwiki/xwiki-platform/commit/98208c5bb1e8cdf3ff1ac35d8b3d1cb3c28b3263#diff-4e3467d2ef3871a68b2f910e67cf84531751b32e0126321be83c0f1ed5d90b29L176-R178
### For more information
If you have any questions or comments about this advisory:
* Open an issue in Jira
XWiki.org https://jira.xwiki.org/
* Email us at [Security Mailing List](mailto:security@xwiki.org)