6.8 Unix / Linux Security Enhancements

6.8 Unix / Linux Security Enhancements

1. Operating system hardening is the process of implementing a number of different security practises together to tighten up security

   • disable and remove unnecessary commands, functions and services
   • Tighten file system permissions. Use the principle of least privilege
   • Review user account password strength, if you can crack it so can a hacker. Enforce complexity
   • Vet all SetUID files
     • Ensure the SetUID command is only available to those files you really need
   • Apply security patches. Easy to attack a system with known unpatched vulnerabilities

2. Host based intrusion detection

   • File integrity checking
   • log analysis
   • anomaly detection
   • audit trail generation

3. A different way to secure Unix is to make modifications to the Kernel and build security features

   • Using Open source Linux is the perfect way to do this
     • SELinux
       • Developed by the NSA - Security enhanced linux
     • HP-LX
       • combination of proprietary and open source

4. OpenBSD

   • Like Linux is a completely different unix based OS
     • OpenBSD approach involves scrutinising the source code and fixing any program errors.
       • Effective because most security errors arise because of programming errors
     • Key to success of BSD is the methodical approach and the fact that the install is secure by default
     • You must enable services in order to turn them on
       • nothing on by default