diff --git a/l2tpns.c b/l2tpns.c
index f5ccff9..53011b2 100644
--- a/l2tpns.c
+++ b/l2tpns.c
@@ -4715,6 +4715,7 @@ void processudp(uint8_t *buf, int len, struct sockaddr_in *addr, uint16_t indexu
 					{
 						if (n <= sizeof(authresp))
 						{
+						  memset(authresp, 0, sizeof(authresp));
 							memcpy(authresp, b, n);
 							authrespn = n;
 							LOG(4, s, t, "   Proxy Auth Response\n");