Impact
Anyone who can edit an arbitrary wiki page in an XWiki installation can gain programming right through several cases of missing escaping in the code for displaying sections in the administration interface. This impacts the confidentiality, integrity and availability of the whole XWiki installation. Normally, all users are allowed to edit their own user profile so this should be exploitable by all users of the XWiki instance.
The easiest way to reproduce this is to edit any document with the object editor and add an object of type XWiki.ConfigurableClass ("Custom configurable sections"). Set "Display in section" and "Display in Category" to "other", set scope to "Wiki and all spaces" and "Heading" to {{async}}{{groovy}}services.logging.getLogger("attacker").error("Attack from Heading succeeded!"); println("Hello from Groovy!"){{/groovy}}{{/async}}. Click "Save". Open <xwiki-host>/xwiki/bin/view/Main/?sheet=XWiki.AdminSheet&viewer=content&editor=globaladmin§ion=other where <xwiki-host> is the URL of your XWiki installation. If this displays just "Hello from Groovy!" in a heading and generates an error message with content "Attack from Heading succeeded!" in XWiki's log, the attack succeeded. Similar attacks are also possible by creating this kind of object on a document with a specially crafted name, see the referenced Jira issues for more reproduction steps.
Patches
This has been fixed in XWiki 14.10.15, 15.5.2 and 15.7RC1
Workarounds
It is possible to manually apply the fixes for the vulnerability by editing two pages in the wiki. This patch needs to be applied to the page XWiki.ConfigurableClassMacros. Further, the following patches need to be applied to the page XWiki.ConfigurableClass:
Note that also the page XWiki.ConfigurableClass needs to be changed to xwiki/2.1 syntax for the escaping to work properly but the security vulnerability is fixed also without changing the syntax.
References
Impact
Anyone who can edit an arbitrary wiki page in an XWiki installation can gain programming right through several cases of missing escaping in the code for displaying sections in the administration interface. This impacts the confidentiality, integrity and availability of the whole XWiki installation. Normally, all users are allowed to edit their own user profile so this should be exploitable by all users of the XWiki instance.
The easiest way to reproduce this is to edit any document with the object editor and add an object of type
XWiki.ConfigurableClass("Custom configurable sections"). Set "Display in section" and "Display in Category" to "other", set scope to "Wiki and all spaces" and "Heading" to{{async}}{{groovy}}services.logging.getLogger("attacker").error("Attack from Heading succeeded!"); println("Hello from Groovy!"){{/groovy}}{{/async}}. Click "Save". Open<xwiki-host>/xwiki/bin/view/Main/?sheet=XWiki.AdminSheet&viewer=content&editor=globaladmin§ion=otherwhere<xwiki-host>is the URL of your XWiki installation. If this displays just "Hello from Groovy!" in a heading and generates an error message with content "Attack from Heading succeeded!" in XWiki's log, the attack succeeded. Similar attacks are also possible by creating this kind of object on a document with a specially crafted name, see the referenced Jira issues for more reproduction steps.Patches
This has been fixed in XWiki 14.10.15, 15.5.2 and 15.7RC1
Workarounds
It is possible to manually apply the fixes for the vulnerability by editing two pages in the wiki. This patch needs to be applied to the page
XWiki.ConfigurableClassMacros. Further, the following patches need to be applied to the pageXWiki.ConfigurableClass:Note that also the page
XWiki.ConfigurableClassneeds to be changed toxwiki/2.1syntax for the escaping to work properly but the security vulnerability is fixed also without changing the syntax.References