An issue was discovered in Ignite Realtime Spark 2.8.3 (and the ROAR plugin for it) on Windows. A chat message can include an IMG element with a SRC attribute referencing an external host's IP address. Upon access to this external host, the (NT)LM hashes of the user are sent with the HTTP request. This allows an attacker to collect these hashes, crack them, and potentially compromise the computer. (ROAR can be configured for automatic access. Also, access can occur if the user clicks.)