AscoServer.exe in the server in Siemens SiPass integrated MP2.6 and earlier does not properly handle IOCP RPC messages received over an Ethernet network, which allows remote attackers to write data to any memory location and consequently execute arbitrary code via crafted messages, as demonstrated by an arbitrary pointer dereference attack or a buffer overflow attack.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.