Senior Linux System Administrator - Security & Hardening

CACI International Inc; Washington (District of Columbia); On-site; USD 90,000 - 190,000; Full time

Job summary

CA CI International Inc. is seeking a Linux System Administrator to support the FEMA Office of the Chief Information Security Officer in Washington, D.C.

You will secure Linux-based infrastructure, implement DISA STIGs or CIS Benchmarks, and maintain high availability across on-premises and hybrid environments. You will collaborate with cybersecurity professionals, system owners, and enterprise admins to manage patching, logging, and access controls while ensuring system integrity and threat

Qualifications

• U.S. citizenship required.
• FEMA EOD suitability or DHS/FEMA EOD preferred.
• BS/BA + 8 years of applicable experience or equivalent combination.
• Minimum 7 years of Linux system administration experience.
• Expertise in Linux infrastructure, DISA STIGs, and CIS Benchmarks.
• Experience with security hardening and vulnerability remediation.
• Knowledge of firewalls, access controls, and system service hardening.
• Experience with LDAP, PAM, and identity management solutions.
• Experience with DISA STIGs and security hardening best practices.
• Knowledge of vulnerability remediation and patch management processes.
• Strong understanding of Linux security logging and auditing.
• Experience with VXRails or Zscaler.

Responsibilities

• Secure Linux-based infrastructure for FEMA enterprise across on-premises and hybrid environments.
• Apply DISA STIGs or CIS Benchmarks to reduce attack surfaces and enforce security controls.
• Configure firewalls, access controls, and harden system services.
• Patch, upgrade, and remediate vulnerabilities with minimal operational impact.
• Ensure high availability and uptime through monitoring and capacity planning.
• Support ICAM tools, LDAP, and privileged access management.
• Maintain least privilege principle and robust logging for auditing.
• Document administrative actions and contribute to security assessments.

Skills

Linux system administration

Security hardening

DISA STIGs / CIS Benchmarks

Vulnerability remediation

Firewalls & access controls

Identity management / ICAM

Logging & auditing

Hybrid on-prem / cloud

Education

BS/BA in a related field

Tools

LDAP

PAM

Ansible

Puppet

Chef

VXRails

Zscaler

Job description

CA CI International Inc. is seeking a Linux System Administrator to support the FEMA Office of the Chief Information Security Officer in Washington, D.C.

You will secure Linux-based infrastructure, implement DISA STIGs or CIS Benchmarks, and maintain high availability across on-premises and hybrid environments. You will collaborate with cybersecurity professionals, system owners, and enterprise admins to manage patching, logging, and access controls while ensuring system integrity and threat