diff -r 40aa2248e2a0 -r 9725f7b50000 libpurple/proxy.c
--- a/libpurple/proxy.c	Wed May 14 17:05:26 2014 +0200
+++ b/libpurple/proxy.c	Thu May 15 17:20:31 2014 +0200
@@ -1723,6 +1723,11 @@
 	navas = *cmdbuf;
 
 	purple_debug_misc("socks5 proxy", "Expecting %d attribute(s).\n", navas);
+	if (G_UNLIKELY(navas > 10000)) { /* XXX: what's the threshold? */
+		purple_proxy_connect_data_disconnect(connect_data,
+			_("Received invalid data on connection with server"));
+		return -1;
+	}
 
 	cmdbuf++;