There's a serious vulnerability that affects most Linux Operating Systems, CVE-2016-5195, also known as DIRTY COW
Dirty COW (Dirty copy-on-write) is a computer security vulnerability for the Linux kernel that affects all Linux-based operating systems including Android. It is a local privilege escalation bug that exploits a race condition in the implementation of the copy-on-write mechanism.
The bug has been lurking in the Linux kernel since version 2.6.22 (released in September 2007), and has been actively exploited at least since October 2016. The bug has been patched in Linux kernel versions 4.8.3, 4.7.9, 4.4.26 and newer.
All customers running the affected versions of the kernel are strongly recommended to update the kernel. So if you manage your own server, you will need to update the kernel (and reboot your server) once the security patch is issued by your operating system providers.
If you do not manage your own server or if you are using shared hosting, contact your server administrator or hosting provider to make sure that you are protected against this vulnerability.
System requirements for the Magento application for Magento 2.1.x
- Operating systems (Linux x86-64). Linux distributions such as RedHat Enterprise Linux (RHEL), CentOS, Ubuntu, Debian, and so on
- Memory requirement is up to 2GB of RAM
- Composer is required for developers who wish to contribute to the Magento 2 codebase or anyone who wishes to develop Magento extensions
- Web servers: Apache 2.2 or 2.4 / nginx 1.8
- Database MySQL 5.6
- PHP 5.6.x - 7.0.4
More info: Magento 2.1.x technology stack requirements