Security considerations
One of the most important aspects to consider when designing a new system is security. Depending on the characteristics of the system, the requirements, and the evaluation of the risks, different countermeasures may be appropriate. Security-enhancing features are often a mix of hardware and software efforts to provide specific protections against known attacks.
Vulnerability management
Software components keep evolving as new features are introduced, and defects are fixed along the way. Some of the defects that are discovered and fixed in a later version may impact the security of the system running outdated software if proper action is not taken promptly. Once vulnerabilities in third-party components are fully disclosed to the public, it is no longer a good choice to keep running outdated code.
Older versions with known defects running on public networks have an increased possibility of becoming the attack surface for attempts to damage the system...