chat.ghp in Easy Chat Server 1.2 allows remote attackers to cause a denial of service (server crash) via a long username parameter, possibly due to a buffer overflow. NOTE: it was later reported that 2.2 is also affected.
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.