SharePoint Register Directive Abuses 'publishingribbon' Tagprefix to Hide Unsafe
Detects suspicious HTTP requests directed at SharePoint applications containing a malformed Register directive. The rule identifies attempts to leverage the 'publishingribbon' Tagprefix combined with unauthorized namespaces (e.g., System.Xaml, System.Windows.Data) to bypass the EditingPageParser.InitializeRegisterTable safelist check, a common technique for SharePoint remote code execution.
Microsoft Sentinel (KQL)
