Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 135062)
+++ channels/chan_sip.c	(working copy - again)
@@ -3800,6 +3800,8 @@
 	const char *insecure;
 	while ((cat = ast_category_browse(config, cat))) {
 		insecure = ast_variable_retrieve(config, cat, "insecure");
+		if (!insecure)
+			continue;
 		set_insecure_flags(&flags, insecure, -1);
 		if (ast_test_flag(&flags, SIP_INSECURE_PORT)) {
 			var = ast_category_root(config, cat);