From 264e97625abe2e0334f97de17f6ffb52582888ab Mon Sep 17 00:00:00 2001
From: Albert Astals Cid <aacid@kde.org>
Date: Wed, 10 May 2017 10:06:07 +0200
Subject: Verify that whoever is calling us is actually who he says he is
CVE-2017-8422
---
kdecore/auth/AuthBackend.cpp | 5 ++++
kdecore/auth/AuthBackend.h | 7 ++++++
kdecore/auth/backends/dbus/DBusHelperProxy.cpp | 27 ++++++++++++++++++++--
kdecore/auth/backends/dbus/DBusHelperProxy.h | 6 ++++-
.../auth/backends/policykit/PolicyKitBackend.cpp | 5 ++++
kdecore/auth/backends/policykit/PolicyKitBackend.h | 1 +
kdecore/auth/backends/polkit-1/Polkit1Backend.cpp | 5 ++++
kdecore/auth/backends/polkit-1/Polkit1Backend.h | 1 +
8 files changed, 54 insertions(+), 3 deletions(-)
diff --git a/kdecore/auth/AuthBackend.cpp b/kdecore/auth/AuthBackend.cpp
index c953b81..0ba4650 100644
--- a/kdecore/auth/AuthBackend.cpp
+++ b/kdecore/auth/AuthBackend.cpp
@@ -54,6 +54,11 @@ void AuthBackend::setCapabilities(AuthBackend::Capabilities capabilities)
d->capabilities = capabilities;
}
+AuthBackend::ExtraCallerIDVerificationMethod AuthBackend::extraCallerIDVerificationMethod() const
+{
+ return NoExtraCallerIDVerificationMethod;
+}
+
bool AuthBackend::actionExists(const QString& action)
{
Q_UNUSED(action);
diff --git a/kdecore/auth/AuthBackend.h b/kdecore/auth/AuthBackend.h
index a86732e..6f4b1bc 100644
--- a/kdecore/auth/AuthBackend.h
+++ b/kdecore/auth/AuthBackend.h
@@ -43,6 +43,12 @@ public:
};
Q_DECLARE_FLAGS(Capabilities, Capability)
+ enum ExtraCallerIDVerificationMethod {
+ NoExtraCallerIDVerificationMethod,
+ VerifyAgainstDBusServiceName,
+ VerifyAgainstDBusServicePid,
+ };
+
AuthBackend();
virtual ~AuthBackend();
virtual void setupAction(const QString &action) = 0;
@@ -50,6 +56,7 @@ public:
virtual Action::AuthStatus authorizeAction(const QString &action) = 0;
virtual Action::AuthStatus actionStatus(const QString &action) = 0;
virtual QByteArray callerID() const = 0;
+ virtual ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const;
virtual bool isCallerAuthorized(const QString &action, QByteArray callerID) = 0;
virtual bool actionExists(const QString &action);
diff --git a/kdecore/auth/backends/dbus/DBusHelperProxy.cpp b/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
index 9557a0f..ca59f1c 100644
--- a/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
+++ b/kdecore/auth/backends/dbus/DBusHelperProxy.cpp
@@ -271,6 +271,29 @@ void DBusHelperProxy::performActions(QByteArray blob, const QByteArray &callerID
}
}
+bool DBusHelperProxy::isCallerAuthorized(const QString &action, const QByteArray &callerID)
+{
+ // Check the caller is really who it says it is
+ switch (BackendsManager::authBackend()->extraCallerIDVerificationMethod()) {
+ case AuthBackend::NoExtraCallerIDVerificationMethod:
+ break;
+
+ case AuthBackend::VerifyAgainstDBusServiceName:
+ if (message().service().toUtf8() != callerID) {
+ return false;
+ }
+ break;
+
+ case AuthBackend::VerifyAgainstDBusServicePid:
+ if (connection().interface()->servicePid(message().service()).value() != callerID.toUInt()) {
+ return false;
+ }
+ break;
+ }
+
+ return BackendsManager::authBackend()->isCallerAuthorized(action, callerID);
+}
+
QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArray &callerID, QByteArray arguments)
{
if (!responder) {
@@ -295,7 +318,7 @@ QByteArray DBusHelperProxy::performAction(const QString &action, const QByteArra
QTimer *timer = responder->property("__KAuth_Helper_Shutdown_Timer").value<QTimer*>();
timer->stop();
- if (BackendsManager::authBackend()->isCallerAuthorized(action, callerID)) {
+ if (isCallerAuthorized(action, callerID)) {
QString slotname = action;
if (slotname.startsWith(m_name + QLatin1Char('.'))) {
slotname = slotname.right(slotname.length() - m_name.length() - 1);
@@ -338,7 +361,7 @@ uint DBusHelperProxy::authorizeAction(const QString& action, const QByteArray& c
QTimer *timer = responder->property("__KAuth_Helper_Shutdown_Timer").value<QTimer*>();
timer->stop();
- if (BackendsManager::authBackend()->isCallerAuthorized(action, callerID)) {
+ if (isCallerAuthorized(action, callerID)) {
retVal = static_cast<uint>(Action::Authorized);
} else {
retVal = static_cast<uint>(Action::Denied);
diff --git a/kdecore/auth/backends/dbus/DBusHelperProxy.h b/kdecore/auth/backends/dbus/DBusHelperProxy.h
index 455cf51..264f6cc 100644
--- a/kdecore/auth/backends/dbus/DBusHelperProxy.h
+++ b/kdecore/auth/backends/dbus/DBusHelperProxy.h
@@ -21,6 +21,7 @@
#ifndef DBUS_HELPER_PROXY_H
#define DBUS_HELPER_PROXY_H
+#include <QDBusContext>
#include <QVariant>
#include "HelperProxy.h"
#include "kauthactionreply.h"
@@ -28,7 +29,7 @@
namespace KAuth
{
-class DBusHelperProxy : public HelperProxy
+class DBusHelperProxy : public HelperProxy, protected QDBusContext
{
Q_OBJECT
Q_INTERFACES(KAuth::HelperProxy)
@@ -73,6 +74,9 @@ signals:
private slots:
void remoteSignalReceived(int type, const QString &action, QByteArray blob);
+
+private:
+ bool isCallerAuthorized(const QString &action, const QByteArray &callerID);
};
} // namespace Auth
diff --git a/kdecore/auth/backends/policykit/PolicyKitBackend.cpp b/kdecore/auth/backends/policykit/PolicyKitBackend.cpp
index 3be97f2..9d041d1 100644
--- a/kdecore/auth/backends/policykit/PolicyKitBackend.cpp
+++ b/kdecore/auth/backends/policykit/PolicyKitBackend.cpp
@@ -78,6 +78,11 @@ QByteArray PolicyKitBackend::callerID() const
return a;
}
+AuthBackend::ExtraCallerIDVerificationMethod Polkit1Backend::extraCallerIDVerificationMethod() const
+{
+ return VerifyAgainstDBusServicePid;
+}
+
bool PolicyKitBackend::isCallerAuthorized(const QString &action, QByteArray callerID)
{
QDataStream s(&callerID, QIODevice::ReadOnly);
diff --git a/kdecore/auth/backends/policykit/PolicyKitBackend.h b/kdecore/auth/backends/policykit/PolicyKitBackend.h
index 7154e93..0d3d8f9 100644
--- a/kdecore/auth/backends/policykit/PolicyKitBackend.h
+++ b/kdecore/auth/backends/policykit/PolicyKitBackend.h
@@ -40,6 +40,7 @@ public:
virtual Action::AuthStatus authorizeAction(const QString&);
virtual Action::AuthStatus actionStatus(const QString&);
virtual QByteArray callerID() const;
+ virtual ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const;
virtual bool isCallerAuthorized(const QString &action, QByteArray callerID);
private Q_SLOTS:
diff --git a/kdecore/auth/backends/polkit-1/Polkit1Backend.cpp b/kdecore/auth/backends/polkit-1/Polkit1Backend.cpp
index 732d2cb..63c0e1e 100644
--- a/kdecore/auth/backends/polkit-1/Polkit1Backend.cpp
+++ b/kdecore/auth/backends/polkit-1/Polkit1Backend.cpp
@@ -163,6 +163,11 @@ QByteArray Polkit1Backend::callerID() const
return QDBusConnection::systemBus().baseService().toUtf8();
}
+AuthBackend::ExtraCallerIDVerificationMethod Polkit1Backend::extraCallerIDVerificationMethod() const
+{
+ return VerifyAgainstDBusServiceName;
+}
+
bool Polkit1Backend::isCallerAuthorized(const QString &action, QByteArray callerID)
{
PolkitQt1::SystemBusNameSubject subject(QString::fromUtf8(callerID));
diff --git a/kdecore/auth/backends/polkit-1/Polkit1Backend.h b/kdecore/auth/backends/polkit-1/Polkit1Backend.h
index 18ed1a2..d579da2 100644
--- a/kdecore/auth/backends/polkit-1/Polkit1Backend.h
+++ b/kdecore/auth/backends/polkit-1/Polkit1Backend.h
@@ -48,6 +48,7 @@ public:
virtual Action::AuthStatus authorizeAction(const QString&);
virtual Action::AuthStatus actionStatus(const QString&);
virtual QByteArray callerID() const;
+ virtual ExtraCallerIDVerificationMethod extraCallerIDVerificationMethod() const;
virtual bool isCallerAuthorized(const QString &action, QByteArray callerID);
virtual bool actionExists(const QString& action);
--
cgit v0.11.2
