Microsoft Internet Information Services (IIS) 6.0 allows remote attackers to cause a denial of service (server instability or device hang), and possibly obtain sensitive information (device communication traffic); and might allow attackers with physical access to execute arbitrary code after connecting a data stream to a device COM port; via requests for a URI containing a \'/\' immediately before and after the name of a DOS device, as demonstrated by the /AUX/.aspx URI, which bypasses a blacklist for DOS device requests.