diff -Nur a/utils.c netifd-2019-08-05-5e02f944/utils.c
--- a/utils.c	2020-06-04 11:54:37.287682451 -0700
+++ netifd-2019-08-05-5e02f944/utils.c	2020-06-04 11:58:41.782809397 -0700
@@ -118,9 +118,11 @@
 int
 parse_ip_and_netmask(int af, const char *str, void *addr, unsigned int *netmask)
 {
-	char *astr = alloca(strlen(str) + 1);
+	int len = strlen(str) + 1;
+	char *astr = alloca(len);
+	int ret = 0;
 
-	strcpy(astr, str);
+	strncpy(astr, str, len);
 	if (!split_netmask(astr, netmask, af == AF_INET6))
 		return 0;
 
@@ -132,7 +134,16 @@
 			return 0;
 	}
 
-	return inet_pton(af, astr, addr);
+	ret = inet_pton(af, astr, addr);
+	if ((ret > 0) && (af == AF_INET)) {
+                struct in_addr *ip4_addr = (struct in_addr *)addr;
+                uint32_t host_addr = ntohl(ip4_addr->s_addr);
+
+                if (!IN_CLASSA(host_addr) && !IN_CLASSB(host_addr) && !IN_CLASSC(host_addr)) {
+                        ret = 0;
+                }
+        }
+        return ret;
 }
 
 char *