Many risks are possible from a compromise including using the web server into a source of malware, creating a spam-sending relay, a web or TCP proxy, or other malicious activity. The operating system and packages can be fully patched with security updates and the server can still be compromised based purely on a poor security configuration. Security of web applications first begins with configuring the server itself with strict security in mind. Many will often deploy various layers such as a WAF, IDS, or Mod Security to react in real time to various hacking and threats for HTTP requests. However, securing the entire server and any running services with a high level of security in mind is the first fundamental step to avoid the risk of being hacked or compromised. Default operating system installations and configurations, are not secure. In a typical default installation, many network services which won’t be used in a web server configuration are installed, such as remote registry services, print server service, RAS etc. The more services running on an operating system, the more ports will be left open, thus leaving more open doors for malicious users to abuse. Switch off all unnecessary services and disable them, so next time the server is rebooted, they are not started automatically. Switching off unnecessary services will also give an extra boost to your server performances, by freeing some hardware resources.
Unit 2 Discussion 1: Identifying Layers of Access Control in Linux
Access control is typically achieved by reserving a collection of bits within the general “Flag Register” to indicate the current “access control level”. Certain instructions are restricted so that they are only legal if the “access control level” is at least some minimum value; otherwise the instruction generates an “illegal operation” interrupt.
For example a 2-bit, access control level (levels 0 to 3) would typically be