Shannon Baseband chatroom SDP Attribute Memory Corruption

Shannon Baseband suffers from a memory corruption vulnerability that occurs when the baseband modem processes SDP when setting up a call. SDP supports an attribute chatroom that allows multiple chat properties to be specified. The baseband software allocates a fixed-size buffer for these types, but does not check that the number of properties specified by the SDP is within this bound. This can lead to memory corruption when processing a chatroom attribute that contains more than 12 format types.