diff -Nru ktnef-16.04.3/debian/changelog ktnef-16.04.3/debian/changelog
--- ktnef-16.04.3/debian/changelog	2016-09-30 10:14:33.000000000 +0530
+++ ktnef-16.04.3/debian/changelog	2017-03-01 13:53:49.000000000 +0530
@@ -1,3 +1,13 @@
+ktnef (4:16.04.3-0ubuntu2) yakkety; urgency=medium
+
+  * SECURITY UPDATE: Malicious writes during directory traversal.
+      - debian/patches/directory-traversal.patch
+      - Thanks to Eric Sesterhenn for reporting this issue, Albert Astals Cid for fixing this issue.
+      - No CVE number.
+      - fixes (LP: #1668552)
+
+ -- v.naini <vishnu@vishnunaini.com>  Wed, 01 Mar 2017 13:53:49 +0530
+
 ktnef (4:16.04.3-0ubuntu1) yakkety; urgency=medium
 
   [ Scarlett Clark ]
diff -Nru ktnef-16.04.3/debian/patches/directory-taversal.patch ktnef-16.04.3/debian/patches/directory-taversal.patch
--- ktnef-16.04.3/debian/patches/directory-taversal.patch	1970-01-01 05:30:00.000000000 +0530
+++ ktnef-16.04.3/debian/patches/directory-taversal.patch	2017-03-01 13:53:39.000000000 +0530
@@ -0,0 +1,58 @@
+From 4ff38aa15487d69021aacad4b078500f77fb4ae8 Mon Sep 17 00:00:00 2001
+From: Albert Astals Cid <aacid@kde.org>
+Date: Mon, 27 Feb 2017 19:03:49 +0100
+Subject: Fix Directory Traversal problem in ktnef
+
+Reported by Eric Sesterhenn
+
+Patch reviewed by Laurent Montel
+
+CCMAIL: eric.sesterhenn@x41-dsec.de
+---
+ src/ktnefparser.cpp | 15 ++++++++++++++-
+ 1 file changed, 14 insertions(+), 1 deletion(-)
+
+diff --git a/src/ktnefparser.cpp b/src/ktnefparser.cpp
+index ce40e40..0678003 100644
+--- a/src/ktnefparser.cpp
++++ b/src/ktnefparser.cpp
+@@ -41,7 +41,9 @@
+ 
+ #include <QtCore/QDateTime>
+ #include <QtCore/QDataStream>
++#include <QtCore/QDir>
+ #include <QtCore/QFile>
++#include <QtCore/QFileInfo>
+ #include <QtCore/QVariant>
+ #include <QtCore/QList>
+ 
+@@ -446,7 +448,9 @@ bool KTNEFParser::extractFile(const QString &filename) const
+ bool KTNEFParser::ParserPrivate::extractAttachmentTo(KTNEFAttach *att,
+         const QString &dirname)
+ {
+-    QString filename = dirname + QLatin1Char('/');
++    const QString destDir(QDir(dirname).absolutePath()); // get directory path without any "." or ".."
++
++    QString filename = destDir + QLatin1Char('/');
+     if (!att->fileName().isEmpty()) {
+         filename += att->fileName();
+     } else {
+@@ -462,6 +466,15 @@ bool KTNEFParser::ParserPrivate::extractAttachmentTo(KTNEFAttach *att,
+     if (!device_->seek(att->offset())) {
+         return false;
+     }
++
++    const QFileInfo fi(filename);
++    if (!fi.absoluteFilePath().startsWith(destDir)) {
++        qWarning() << "Attempted extract into" << fi.absoluteFilePath()
++                   << "which is outside of the extraction root folder" << destDir << "."
++                   << "Changing export of contained files to extraction root folder.";
++        filename = destDir + QLatin1Char('/') + fi.fileName();
++    }
++
+     QSaveFile outfile(filename);
+     if (!outfile.open(QIODevice::WriteOnly)) {
+         return false;
+-- 
+cgit v0.11.2
+
diff -Nru ktnef-16.04.3/debian/patches/series ktnef-16.04.3/debian/patches/series
--- ktnef-16.04.3/debian/patches/series	1970-01-01 05:30:00.000000000 +0530
+++ ktnef-16.04.3/debian/patches/series	2017-03-01 13:53:39.000000000 +0530
@@ -0,0 +1 @@
+directory-taversal.patch