description: An issue was discovered in OpenNDS Captive Portal before 10.1.2. it has a do_binauth NULL pointer dereference that can be triggered with a crafted GET HTTP request with a missing client redirect query string parameter. Triggering this issue results in crashing openNDS (a Denial-of-Service condition). The issue occurs when the client is about to be authenticated, and can be triggered only when the BinAuth option is set.