Operating system hardening is the process to address security weaknesses in the operation systems by implementing the latest operating system patches, hot fixes and updates as well as follow up the specific procedures and policies to reduce attacks and system down time.
Patra, P.K . Prof. (Dr.) and Pradhan, P.L.
"Hardening of UNIX Operating System,"
International Journal of Computer and Communication Technology: Vol. 1
, Article 9.
Available at: https://www.interscience.in/ijcct/vol1/iss1/9