File 0001-Remove-support-for-passing-gui-QVariants-t... of Package mingw32-kdelibs4

Overview Repositories Revisions Requests Users Attributes Meta

File 0001-Remove-support-for-passing-gui-QVariants-to-KAuth-he.patch of Package mingw32-kdelibs4 (Revision 750c6b1aff6031f3b3b9ea175ccc7e78)

Currently displaying revision 750c6b1aff6031f3b3b9ea175ccc7e78 , Show latest

From 2eec34cb7a2b1688eb8a82a7f249ed9fe5254af3 Mon Sep 17 00:00:00 2001
From: Ralf Habacker <ralf.habacker@freenet.de>
Date: Wed, 20 Mar 2019 11:09:29 +0100
Subject: [PATCH] Remove support for passing gui QVariants to KAuth helpers

Supporting gui variants is very dangerous since they can end up triggering
image loading plugins which are one of the biggest vectors for crashes, which
for very smart people mean possible code execution, which is very dangerous
in code that is executed as root.

We've checked all the KAuth helpers inside KDE git and none seems to be using
gui variants, so we're not actually limiting anything that people wanted to do.

Reviewed by security@kde.org and Aleix Pol

Issue reported by Fabian Vogt

CVE: CVE-2019-7443
---
 kdecore/auth/backends/dbus/DBusHelperProxy.cpp | 9 +++++++++
 kdecore/auth/kauthaction.h                     | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/kdecore/auth/backends/dbus/DBusHelperProxy.cpp b/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
index ca59f1c..2f388ed 100644
--- a/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
+++ b/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
@@ -37,6 +37,8 @@
 
 Q_DECLARE_METATYPE(QTimer*)
 
+extern Q_CORE_EXPORT const void* qMetaTypeGuiHelper;
+
 namespace KAuth
 {
 
@@ -304,10 +306,17 @@ QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArra
         return ActionReply::HelperBusyReply.serialized();
     }
 
+    // Make sure we don't try restoring gui variants, in particular QImage/QPixmap/QIcon are super dangerous
+    // since they end up calling the image loaders and thus are a vector for crashing → executing code
+    const void* origMetaTypeGuiHelper = qMetaTypeGuiHelper;
+    qMetaTypeGuiHelper = NULL;
+
     QVariantMap args;
     QDataStream s(&arguments, QIODevice::ReadOnly);
     s >> args;
 
+    qMetaTypeGuiHelper = origMetaTypeGuiHelper;
+
     m_currentAction = action;
     emit remoteSignal(ActionStarted, action, QByteArray());
     QEventLoop e;
diff --git a/kdecore/auth/kauthaction.h b/kdecore/auth/kauthaction.h
index 123883b..ce5011a 100644
--- a/kdecore/auth/kauthaction.h
+++ b/kdecore/auth/kauthaction.h
@@ -270,6 +270,8 @@ public:
      * This method sets the variant map that the application
      * can use to pass arbitrary data to the helper when executing the action.
      *
+     * Only non-gui variants are supported.
+     *
      * @param arguments The new arguments map
      */
     void setArguments(const QVariantMap &arguments);
-- 
1.8.4.5

Places

File 0001-Remove-support-for-passing-gui-QVariants-to-KAuth-he.patch of Package mingw32-kdelibs4 (Revision 750c6b1aff6031f3b3b9ea175ccc7e78)

Places