commit 4cfed6b0a625593fb43876f04badc4dd99799d86
Author: David Edmundson <kde@davidedmundson.co.uk>
Date:   Wed Oct 14 00:08:59 2015 +0100

    Disable greeters from loading KDE's debug hander
    
    Some themes may use KDE components which will automatically load KDE's
    crash handler.
    
    If the greeter were to then somehow crash, that would leave a crash
    handler allowing other actions, albeit as the locked down SDDM user.
    
    Only SDDM users using the breeze theme from plasma-workspace are
    affected. Safest and simplest fix is to handle this inside SDDM
    disabling kcrash via an environment variable for all future themes that
    may use these libraries.
    
    CVE-2015-0856

diff --git a/src/daemon/Greeter.cpp b/src/daemon/Greeter.cpp
index 68c4dc3..8c936b7 100644
--- a/src/daemon/Greeter.cpp
+++ b/src/daemon/Greeter.cpp
@@ -145,6 +145,10 @@ namespace SDDM {
             env.insert(QStringLiteral("XDG_VTNR"), QString::number(m_display->terminalId()));
             env.insert(QStringLiteral("XDG_SESSION_CLASS"), QStringLiteral("greeter"));
             env.insert(QStringLiteral("XDG_SESSION_TYPE"), m_display->sessionType());
+
+            //some themes may use KDE components and that will automatically load KDE's crash handler which we don't want
+            //counterintuitively setting this env disables that handler
+            env.insert(QStringLiteral("KDE_DEBUG"), QStringLiteral("1"));
             m_auth->insertEnvironment(env);
 
             // log message