Introduction

After years of STIG assessments and remediation projects, certain mistakes appear repeatedly across organizations. This guide highlights the most common pitfalls and provides actionable advice to help you avoid them.

Mistake #1: Using Outdated STIGs

The Problem

Organizations often use outdated STIG versions, missing critical security updates and failing current compliance requirements. STIGs are updated quarterly, and using old versions can result in:

• Missing new vulnerability mitigations
• Wasting time on deprecated checks
• Failed audits and compliance assessments

The Solution

• Subscribe to DISA STIG announcements at public.cyber.mil/stigs
• Establish a quarterly STIG update process
• Maintain an inventory of which STIG versions apply to each system
• Test new STIG versions in development before production rollout

Mistake #2: Ignoring Category III Findings

The Problem

Teams focus exclusively on Category I and II findings while neglecting Category III. While lower severity, these findings still represent security weaknesses and can compound to create larger risks.

The Solution

• Address all findings systematically, prioritizing by category but not ignoring any
• Category III findings are often quick fixes—knock them out efficiently
• Aim for 100% compliance, not just "good enough"
• Category III compliance demonstrates security maturity to assessors

Mistake #3: Poor Documentation Practices

The Problem

Inadequate documentation of implementations, exceptions, and compensating controls leads to:

• Repeated auditor questions and delays
• Knowledge loss when staff turnover occurs
• Difficulty demonstrating compliance
• Rejection of risk acceptances

The Solution

Maintain comprehensive documentation including:

• Implementation Details: How each STIG requirement was satisfied
• Exception Justifications: Technical/operational reasons for non-compliance
• Compensating Controls: Alternative controls that reduce risk
• Evidence Collection: Screenshots, configuration files, scan results
• Approval Chains: Who authorized exceptions and when

Use standardized templates and maintain documentation in a centralized knowledge base.

Mistake #4: Running Non-Credentialed Scans

The Problem

Non-credentialed scans cannot access system internals, resulting in:

• Inaccurate results with many "Cannot Determine" findings
• False sense of security
• Additional manual verification work
• Assessor skepticism of results

The Solution

• Always use administrative credentials for STIG scans
• Configure scanning tools with appropriate permissions
• Use service accounts with documented, rotated credentials
• Validate scan accuracy by spot-checking results manually

Mistake #5: Applying STIGs Without Testing

The Problem

Implementing STIG configurations directly in production without testing can break applications, disrupt operations, and create downtime. Some STIG settings are aggressive and can impact functionality.

The Solution

• Maintain development/test environments that mirror production
• Apply STIG configurations to test systems first
• Perform functional testing after applying each STIG
• Document any compatibility issues discovered
• Use phased rollouts for large-scale implementations
• Have rollback procedures ready

Mistake #6: Treating STIG Compliance as One-Time Event

The Problem

Organizations achieve compliance then immediately begin to drift due to:

• Configuration changes
• Software updates
• Emergency patches
• Staff actions

The Solution

Implement continuous monitoring:

• Schedule automated weekly or monthly scans
• Alert on new findings immediately
• Integrate STIG checks into change management
• Require STIG compliance scans before production deployment
• Track compliance trends over time

Conclusion

Learning from these common mistakes can save your organization time, money, and security headaches. STIG compliance is achievable with proper planning, documentation, automation, and continuous attention. Treat it as an ongoing security practice, not a checkbox exercise, and you'll build more secure systems while satisfying compliance requirements.