Systems Administrator (Linux / RHEL)

General Dynamics Information Technology

18h•$89,250 - $120,750•Onsite

About The Position

The Compliance Systems Administrator (Linux / RHEL) plays a critical, hands-on role in securing and maintaining enterprise Red Hat Enterprise Linux (RHEL) and Unix-based operating systems. This position is responsible for the direct technical execution of system hardening, patching, identity integration, and vulnerability remediation to ensure Linux servers and appliances adhere to Department of War (DoW) cybersecurity standards in preparation for CORA cyber inspections.

Requirements

Applicable Intermediate DoW 8140 or DoW 8570 Certification (e.g., Security+ CE, CySA+, Linux+, or SSCP).
Bachelor's Degree in a related discipline OR three (3) years of hands-on experience administering and hardening Red Hat Enterprise Linux (RHEL) environments.
Direct experience in Linux system administration, command-line operations (CLI), user management, and package patching.
Hands-on experience applying DISA STIGs to RHEL systems using SCAP Compliance Checker (SCC) or OpenSCAP.
Familiarity with reviewing ACAS/Tenable vulnerability reports and executing Linux-specific remediation steps.
Understanding of PKI certificate installation and PAM/SSSD authentication integration.
Active Secret clearance.

Nice To Haves

Red Hat Certified System Administrator (RHCSA) or Red Hat Certified Engineer (RHCE).
Experience supporting USCENTCOM Linux server infrastructure.
Hands-on experience writing Ansible playbooks and Bash scripts for STIG compliance automation.
Experience with Red Hat Satellite Server for centralized lifecycle and errata management.
Experience preparing Linux systems for DoD Cyber Defense Command (DCDC) Cyber Operational Risk Assessments (CORA).

Responsibilities

Remediate security findings identified through ACAS/Tenable reports and OpenSCAP scans by performing hands-on system patching, configuration updates, and service hardening on RHEL 8/9 systems.
Technically implement and maintain compliance with Red Hat Enterprise Linux DISA STIGs, Cyber Tasking Orders (CTOs), and IAVM notices.
Configure, troubleshoot, and enforce mandatory access controls using SELinux (Security-Enhanced Linux) in enforcing mode.
Manage and maintain central identity, PAM (Pluggable Authentication Modules), SSSD, and DoW PKI/CAC authentication mechanisms for user and administrative access.
Configure and maintain host-based firewalls (firewalled/iptables) and audit daemon logging (audited) in strict compliance with DoW auditing requirements.
Utilize package management tools (YUM/DNF), Red Hat Satellite, or local repositories to deploy security errata and software updates across air-gapped or restricted networks.
Develop and execute Bash and Ansible playbooks to automate STIG hardening, configuration audits, and compliance validation.
Develop, implement, and document technical mitigation strategies and POA&Ms for system-specific Linux vulnerabilities that cannot be immediately fixed.
Compile technical evidence, OpenSCAP evaluation reports, and configuration artifacts for CORA inspection teams.