From 44a3859dc95e39df6a4bedc66e688f6b5090c5fa Mon Sep 17 00:00:00 2001
From: Qasim Ayyaz Khan <qasimakhan@gmail.com>
Date: Wed, 13 Jun 2018 08:00:11 +0000
Subject: [PATCH] Patch for Malformed PDU with cmdLength 0. Issue #25.

---
 lib/session.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/session.js b/lib/session.js
index b1fd6fe..0f21d22 100644
--- a/lib/session.js
+++ b/lib/session.js
@@ -641,6 +641,16 @@ function session(sock) {
 		while (returnObj.dataQueue.length > 4) {
 			const	cmdLength	= parseInt(returnObj.dataQueue.readUInt32BE(0));	// Get this commands length
 
+                        // Malformed PDU with command length 0
+                        if (cmdLength <= 0) {
+                                // Since PDU is Malformed we need to discard buffer.
+                                log.silly(thisLogPrefix + 'Malformed PDU with 0 Length. Discarding buffer.');
+                                returnObj.dataQueue = returnObj.dataQueue.slice(0, returnObj.dataQueue.length);
+
+                                // Since PDU is malformed we need to close socket since we cannot trust data from now on.
+                                returnObj.closeSocket();
+                        }
+
 			let	pdu;
 
 			log.silly(thisLogPrefix + 'Processing ' + cmdLength + ' bytes of data');