CA-8: Penetration Testing

CA-8 is one of those controls that fails in practice for a simple reason: teams run a penetration test, but they cannot prove it was conducted on the right systems, with the right intent, under the right authorization, and with findings actually remediated. For a Compliance Officer, CCO, or GRC lead, the goal is not to become a pen tester. The goal is to make penetration testing a repeatable, governed activity that maps to your environment and produces clean evidence for assessors.

The control text is short, but it contains two operator-defined parameters: how often you test and what you test. That flexibility is useful, but it also creates audit exposure if you cannot justify your choices or if the program drifts from what you documented. CA-8 also has strong dependencies: if your asset inventory is incomplete, your scope will be wrong; if your vulnerability management and change management are weak, findings will not close; if your third-party governance is thin, external testers may create risk instead of reducing it.

This page turns CA-8 into an execution checklist you can assign to an owner, monitor, and defend during an assessment, while keeping the documentation burden reasonable. Sources: NIST SP 800-53 Rev. 5; NIST SP 800-53 Rev. 5 OSCAL JSON.

Regulatory text

Requirement (verbatim): “Conduct penetration testing {{ insert: param, ca-08_odp.01 }} on {{ insert: param, ca-08_odp.02 }}.” ¹

How to read the parameters as an operator

• “{{…ca-08_odp.01}}” = the frequency/conditions you define (for example, a recurring schedule and/or event-driven triggers such as major releases).
• “{{…ca-08_odp.02}}” = the scope/targets you define (for example, specific systems, environments, applications, or networks).

What you must do to satisfy the text

1. Decide and document when penetration tests occur and what they cover.
2. Execute penetration testing according to that documented plan.
3. Maintain evidence that testing occurred and that you handled results through remediation and verification.

This is a governance control as much as a technical activity. The assessor will look for a clear, consistent chain: scoping decision → authorized testing → results → fixes → closure. ²

Plain-English interpretation (what CA-8 is really asking)

CA-8 asks: “Do you regularly prove your defenses by simulating real attacker behavior against defined targets, and can you show the work?” Vulnerability scans and automated tooling are not substitutes for CA-8 in an audit argument. Pen testing is adversarial and path-based: testers chain weaknesses (identity, segmentation, misconfigurations, app flaws, exposed secrets) to reach high-impact outcomes.

From a GRC standpoint, the control is “medium” severity in your baseline sense-making, but the operational risk can be high if the assets in scope include sensitive data, mission-critical services, or externally exposed systems. ²

Who it applies to (entity and operational context)

CA-8 commonly applies when you:

• Operate a federal information system or are assessed against NIST SP 800-53 controls. ²
• Are a contractor system handling federal data and must demonstrate 800-53-aligned security assessment practices to customers, primes, or assessors. ²

Operationally, it applies wherever you have:

• Externally accessible attack surface (public apps, APIs, VPN, identity providers).
• Material internal lateral-movement risk (flat networks, privileged identity sprawl).
• Complex third-party dependencies (SaaS, managed hosting, MSP/MSSP, outsourced development), because pen tests often require coordination across boundary lines.

What you actually need to do (step-by-step)

1) Assign ownership and define the “control statement”

Set a single accountable owner (often Security Assurance, AppSec, or Security Engineering) and write a short CA-8 implementation statement that answers:

• What penetration testing means in your org (network, web app, API, cloud control plane, internal, external).
• Your frequency and triggers (the “odps” in the control text).
• Your target scope categories and exclusions, with justification. ¹

Deliverable: CA-8 control narrative + RACI.

2) Define scope using systems and data, not org charts

Build pen test scope from:

• Asset inventory (systems, applications, cloud accounts/projects/subscriptions).
• Data classification and trust boundaries (where regulated/sensitive data lives and moves).
• Internet exposure and identity/control-plane entry points.

Practical scoping rules that hold up in audits

• Name the specific targets (apps, CIDRs, URLs, repos, cloud tenants).
• Identify in-scope environments (production vs. pre-prod) and justify if production is excluded.
• Include representative user roles and privileged paths (admin portals, SSO flows, service accounts).

Deliverable: Scope document with target list, diagrams, and testing assumptions.

3) Write Rules of Engagement (RoE) that reduce operational risk

Your RoE should be short, signed, and operational:

• Approved testing windows and blackout periods.
• Allowed techniques (social engineering allowed or prohibited; DoS explicitly prohibited unless separately approved).
• Data handling rules (how testers store evidence, where reports reside, retention, and secure transfer).
• Communications plan (real-time escalation path, “stop test” authority).
• Logging/monitoring coordination (so SOC can distinguish test activity without suppressing real alerts).

Deliverable: Rules of Engagement + approval record.

4) Select qualified testers and manage the third party like a high-risk engagement

If you use an external pen test firm (a third party), treat it as a controlled engagement:

• Contractual confidentiality and data handling terms.
• Named tester identities (or at least controlled access provisioning).
• Background/access constraints appropriate to your environment.
• Clear deliverables: executive summary, technical findings, evidence, reproduction steps, severity rationale.

If internal testing is used, confirm independence from the system owners being tested (at least at the reporting line / approval layer) so results are credible. ²

Deliverable: SOW/engagement letter, tester qualifications summary, access approvals.

5) Execute testing and ensure monitoring/incident processes stay intact

Run the test with:

• Kickoff with stakeholders (system owners, SOC, IT ops, change manager).
• Confirmed target list and access method (black/gray/white box).
• Daily status updates for longer engagements and immediate notification for critical exploitation.

Avoid “silent testing” that triggers an incident response scramble without a pre-brief. That is operationally expensive and often results in the wrong lesson learned.

Deliverable: Testing timeline, activity logs (as available), and final report.

6) Triage findings into an accountable remediation plan

Pen test results are only as good as the fix-through:

• Convert each finding into a ticket with owner, due date, and acceptance criteria.
• Tag tickets as “Pen Test Finding” for reporting and evidence.
• Require a disposition: remediate, mitigate with compensating controls, or formally accept risk with sign-off.

Deliverable: Remediation tracker (tickets), risk acceptances, and compensating control documentation.

7) Verify closure (retest) and document residual risk

A common audit hangup: “You fixed it” without proof. For high-impact findings, require retest evidence:

• Retest by the tester or internal security team.
• Evidence artifacts (screenshots, command output, updated configuration state) stored with the ticket.

If something cannot be fixed quickly, document interim safeguards and a committed remediation plan tied to change management.

Deliverable: Retest results, closure notes, residual risk statements.

8) Report, trend, and feed your risk register

Your CA-8 program should produce governance outputs:

• A management summary: themes, systemic issues, and control gaps.
• Updates to the risk register and POA&M-like tracking if your program uses that structure.
• Link recurring findings to upstream controls (secure configuration, IAM, SDLC, patching).

Deliverable: Summary report, metrics dashboard (qualitative is fine), and risk register updates.

Required evidence and artifacts to retain (audit-ready list)

Use this as your CA-8 evidence checklist:

• CA-8 control narrative (frequency + scope defined) ¹
• Pen test policy/standard or procedure (how pen tests are initiated and governed)
• Current scope document with target inventory and diagrams
• Rules of Engagement and signed authorization to test
• Tester selection records (internal team charter or third-party SOW)
• Final penetration test report(s), including methodology, scope confirmation, and findings
• Remediation tickets mapped to findings (with timestamps, owners, and closure evidence)
• Risk acceptance memos for deferred items (with approver)
• Retest evidence and closure confirmation
• Lessons learned / systemic corrective actions (optional but helpful in mature programs)

If you want this to run cleanly every cycle, Daydream-style control operations helps by mapping CA-8 to an owner, a repeatable procedure, and a consistent evidence set that you can export for assessments without scrambling. ¹

Common exam/audit questions and hangups

Assessors tend to drill into these points:

• “Show me your defined frequency and scope.” If you cannot produce a document that answers both parameters, CA-8 becomes subjective. ¹
• “How did you choose targets?” Expect scrutiny on inventory completeness and whether high-risk systems were excluded without justification.
• “Prove findings were remediated.” They will sample findings and trace them to closure evidence.
• “Who authorized the testing?” Especially for production and for social engineering scenarios.
• “How do you prevent pen testing from causing outages or data exposure?” RoE quality and operational coordination matter.

Frequent implementation mistakes and how to avoid them

1. Mistake: “Annual pen test” with no defined scope logic.
   Fix: Tie scope to systems, data, and exposure. Keep a living target list.

2. Mistake: Testing only a staging environment with different controls than production.
   Fix: If production is excluded, document why and add compensating assurance (for example, production configuration review plus limited production validation).

3. Mistake: Treating the report as the end.
   Fix: Require a remediation workflow with retest. CA-8 is defensible when you show closure discipline.

4. Mistake: No written authorization or weak RoE.
   Fix: Standardize an RoE template, require signatures, and store it with the report.

5. Mistake: Findings get reintroduced.
   Fix: Connect repeat findings to root causes (baseline hardening, SDLC gates, IAM standards) and track corrective actions at the program level.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for CA-8, so this page does not cite enforcement actions. From a risk standpoint, CA-8 failures typically show up indirectly: breaches trace back to attack paths that a well-scoped pen test could have identified, and audits cite weak security assessment governance when testing is ad hoc or undocumented. ²

Practical execution plan (30/60/90-day)

You asked for speed, but the playbook rules prohibit unsourced elapsed-day timelines. Use phases instead:

Immediate (get audit-safe quickly)

• Assign CA-8 owner and write the control narrative (frequency + scope).
• Create RoE template and an authorization workflow.
• Define your target selection method (inventory + exposure + sensitive data).
• Stand up a remediation tracker that maps findings to tickets and closure evidence.

Near-term (run the first cycle end-to-end)

• Finalize scope for the next engagement; confirm system owner buy-in.
• Select internal testers or contract a third party; complete access provisioning.
• Execute testing with SOC and change management coordination.
• Triage findings, open tickets, and produce a management summary.

Ongoing (make it repeatable)

• Retest high-impact items and document closure.
• Update scope based on architecture changes and new external exposure.
• Trend themes and feed systemic fixes into configuration baselines and SDLC controls.
• Store evidence in a single system of record so audits are exportable without manual stitching.

Frequently Asked Questions

What frequency satisfies the ca-8: penetration testing requirement?

CA-8 requires you to define the frequency as an organization parameter and then execute to it. Pick a cadence and triggers you can defend based on system criticality and change rate, then document and follow it. ¹

Does CA-8 require external third-party penetration testers?

The control text requires penetration testing, not a specific sourcing model. External testers can improve independence, but internal teams can satisfy the requirement if the engagement is authorized, scoped, documented, and results are remediated with evidence. ²

Can vulnerability scanning count as penetration testing for CA-8?

A vulnerability scan supports security testing, but CA-8 explicitly calls for penetration testing. Pen testing is attacker-path focused and should validate exploitability and impact within the defined scope. ²

How do we handle SaaS systems we don’t control?

Define whether the SaaS tenant is in scope and test what you can (configuration, identity flows, integrations, and exposed data paths) while using third-party assurance for the provider’s underlying platform. Document boundaries and compensating evidence in your scope statement.

What if a critical finding can’t be remediated quickly?

Document the decision and keep it governed: open a ticket, implement compensating controls where possible, and record a formal risk acceptance with an approver and planned remediation path. Retain this with the pen test evidence package.

What evidence is most likely to be sampled in an audit?

Expect sampling of the scope/authorization, the final report, and a trace from selected findings to remediation and retest evidence. If you can produce that chain quickly, CA-8 discussions stay short and factual. ¹

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5