From af24e30ae9f85e346e109e91fb034372f965759c Mon Sep 17 00:00:00 2001
From: HD Moore <hd_moore@rapid7.com>
Date: Sat, 6 Sep 2014 15:51:50 -0500
Subject: [PATCH] Return instead of crashing if no challenge is received

---
 lib/rex/proto/iax2/call.rb | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/rex/proto/iax2/call.rb b/lib/rex/proto/iax2/call.rb
index 8f13f8323b..f0711f1b75 100644
--- a/lib/rex/proto/iax2/call.rb
+++ b/lib/rex/proto/iax2/call.rb
@@ -77,6 +77,11 @@ class Call
       chall = res[2][IAX_IE_CHALLENGE_DATA]
     end
 
+    if chall.nil?
+      dprint("REGAUTH: No challenge data received")
+      return
+    end
+
     self.client.send_regreq_chall_response(self, chall)
     res = wait_for( IAX_SUBTYPE_REGACK, IAX_SUBTYPE_REGREJ )
     return if not res