Integer overflow in the getword function in options.c in pppd in Paul's PPP Package (ppp) before 2.4.7 allows attackers to "access privileged options" via a long word in an options file, which triggers a heap-based buffer overflow that "[corrupts] security-relevant variables."
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.