Last week, Google has released the 4.4 (KitKat) version of their omni-popular Android OS. Between the improvements, some have noticed several security-related changes. So, how much more secure is Android 4.4?
When talking about Android 4.4 (KitKat) major security improvements, they can be divided into 2 categories:
1. Digital certificates
Android 4.4 will warn the user if a Certificate Authority (CA) is added to the device, making it easy to identify Man-in-the-Middle attacks inside local networks. At the same time, Google Certificate Pinning will make it harder for sophisticated attackers to intercept network traffic to and from Google services, by making sure only whitelisted SSL certificates can connect to certain Google domains.
2. OS hardening
SELinux is now running in enforcing mode, instead of permissive mode. This helps enforce permissions and thwart privilege escalation attacks, such as exploits that want to gain root access. Android 4.4 comes compiled with FORTIFY_SOURCE set at level 2, making buffer overflow exploits harder to implement.
Privilege escalation and buffer overflows are techniques used for rooting mobile phones, so this makes it harder for Android 4.4 users to get root access on their device. On the bright side, it also makes it harder for malware to do the same, which is an important step in the infection of Android based terminals.
From the point of view of malware threats, these enhancements do not really make a big difference. The most common Android infection source remains the same: unofficial apps downloaded from third-party stores. Nothing has changed here.
One of the biggest problems in the Android ecosystem is the big amount of different versions of the OS, including ancient ones, that are still running on users' mobile devices - this is known as version fragmentation. For instance, more than 25% of the users are still running Android 2.3, which has been released years ago. This between other things, represents a big security issue.
Therefore, perhaps the most important change from KitKat is the lowered resource usage. Android 4.4 can run on devices with just 512MB of RAM, which for high end hardware means faster operation and better battery life, while for devices with less resources, the chance to use a modern, more secure OS.
Power users have always wanted to use the latest versions of Android on their devices - that's why phone rooting has become so popular and that's why community projects such as CyanogenMod have evolved into fully-fledged companies.
The real problem here, is the fact that most non-technical users will have to rely on hardware vendors to get an Android update. For instance, I have an old smartphone from a leading mobile phone maker from South Korea, that stopped receiving updates at Android 2.3.3. Sadly, many mobile phone makers prefer to withhold updates as a method of forcing users to purchase newer terminals. At the same time, this is effectively increasing the risk across their entire user base.
It's a pity this problem is not discussed in a wider manner.