There is a stored cross site scripting issue in Esri ArcGIS Server 11.1 and earlier on Windows and Linux that in some configurations allows

There is a stored cross site scripting issue in Esri ArcGIS Server 11.1 and earlier on Windows and Linux that in some configurations allows a remote unauthenticated attacker to store files that contain malicious code that may execute in the context of a victim’s browser. A patch is provided for ArcGIS Server software in General Availability and Extended support status, which includes versions 12.1, 12.0, 11.5, 11.3, and 11.1. Other versions are in mature or retired status, which are not patch eligible. Users working with unlisted versions are advised to upgrade and apply the patch.