Requests were being (incorrectly) processed without checking
whether they include the Upgrade and Connect headers.  The
following patch solves the issue.

commit
Date:   Thu Apr 16 10:10:35 2015 +0200

    [ws]: Ensure WebSocket headers are present

    Requests were (incorrectly) processed without checking whether
    they include the Upgrade and Connect headers.  The following
    patch solves the issue.

diff --git
index 6d60537..a9e0624 100644
---
+++
@@ -431,8 +431,17 @@
 		}
 		dict lappend res protocols {*}$protocols;
 	    }
+	    default {
+		# Ignore other headers.
+	    }
 	}
     }
+    if {!$upgrading} {
+	ThrowError "No 'Connect' header with 'upgrade' token found" HANDSHAKE CONNECTION
+    }
+    if {!$websocket} {
+	ThrowError "No 'Upgrade' header with 'websocket' token found" HANDSHAKE UPGRADE
+    }
     if {![dict exists $res version]} {
 	ThrowError "No WebSocket version specified" HANDSHAKE VERSION
     }