FedRAMP Vulnerability Scanning: Key Stages and Tips to Avoid Common Pitfalls

Vulnerability scanning is one of the most critical — and commonly misunderstood — requirements in achieving the Federal Risk and Authorization Management Program (FedRAMP) Authorization to Operate (ATO). Cloud Service Providers (CSPs) must demonstrate a mature vulnerability management program to meet FedRAMP’s rigorous standards, requiring the right people, processes, and technologies in place. 

In this article, we’ll detail vulnerability scanning and its importance and break down the requirements into three stages: pre-assessment, assessment, and final scans. We’ll also highlight where CSPs often go wrong and how to avoid those common pitfalls so that your organization can stay compliant throughout your FedRAMP journey. 

FedRAMP Vulnerability Scanning: What It Is and Why It Matters 

Vulnerability scanning is a foundational component of the FedRAMP assessment, which governs how CSPs must secure cloud environments used by U.S. federal agencies. While just one element within FedRAMP’s broader security requirements, vulnerability scanning plays an outsized role in determining whether a CSP is granted an ATO.

At its core, vulnerability scanning is the process of systematically evaluating cloud infrastructure, web applications, databases, and other in-scope systems for known security weaknesses. FedRAMP requires CSPs to conduct monthly authenticated scans using up-to-date tools that are capable of identifying critical vulnerabilities and misconfigurations. 

FedRAMP is designed to ensure that federal data stored in the cloud remains secure, resilient, and compliant with government standards. As such, the vulnerability scanning requirements are a measuring stick for your organization’s security maturity, patch and inventory management, and ability to protect key infrastructure. Failing to properly conduct and document scans can delay the authorization process, trigger significant remediation work, or even lead to a denial of an ATO altogether.  

FedRAMP expects CSPs to demonstrate comprehensive coverage and scanning of all components of the system boundary, timely remediation of high-risk vulnerabilities, and any operational constraints, false positives, or disabled scan checks to be formally justified and approved. Because scanning results directly influence the Security Assessment Report (SAR) and ongoing monitoring responsibilities, CSPs who implement a proactive and mature vulnerability management program are better positioned to achieve and maintain long term compliance. 

Three Stages of FedRAMP Vulnerability Scanning 

To meet the FedRAMP requirements and avoid delays in achieving an ATO, CSPs should approach vulnerability scanning as a phased, strategic process. Below are the three key stages of FedRAMP vulnerability scanning—each with their own goals, potential pitfalls, and tips for how to avoid them: 

Stage 1: Pre-Assessment 

Approximately 60-90 days before an expected SAR, a CSP should provide their third-party assessment organization (3PAO) with a recent set of scans, preferably from the most recent three months. The scan data should be provided in a machine-readable format that can be parsed by the 3PAO and agency analysts. If your scanning solution produces a native file format for scans, you should provide that in addition to CSV versions.  

By providing the scan data early, Schellman can identify potential issues that may delay the SAR or result in high severity findings. There are several questions that can be answered by providing scans well ahead of time, including: 

• Credentials: Are the scans being conducted from an authenticated perspective with a user having the highest level of privileges available? 
• All Plugins Enabled: Are any vulnerability checks disabled? 
• Scan Types: Are infrastructure, database, container, compliance and web application scans being performed? 
• Points of Contact: Who is responsible for configuring the scanner and running scans? Who is responsible for remediation? 
• Entire Boundary Covered: Is the full, in-scope environment being scanned? 
• Remediation: Are high severity findings being remediated in 30 days? Are moderate severity findings being remediated within 90 days? 

Within the pre-assessment, one of the most common causes of delays is not having authenticated scans. If the scans are not running authenticated checks, you would either need to provide new scans or document a justification as to why authenticated checks cannot run on a specific host. Not having the correct authentication configured can potentially delay the assessment for up to weeks at a time.   

Having all plugins enabled is frequently an area of discussion, as many CSPs want to disable plugins or sets of checks. Should a check need to be disabled, there must be a documented reason, such as degradation of performance or denial of service occurs with a given plugin. You should not disable checks simply because it is assumed a given type of asset doesn’t exist in the environment. Properly configured and authenticated vulnerability scanners will typically not send families of vulnerability checks against hosts if the operating system or application does not match what is required by the family of checks--i.e., NetWare checks will not be run if NetWare is not detected during the scan of the environment.  

The safest path is to always enable everything. If a given check needs to be disabled, it should be noted as an exception with formal documentation detailing why it is disabled, and what processes are in place to ensure the vulnerability being detected is covered by other mitigating factors. The pre-assessment phase is also a good time for the CSP to document any deviation requests, such as known operational requirements, risk adjustments, and false positives that prevent remediation from occurring. 

Stage 2: Assessment 

During the assessment kickoff, the CSP should be ready for the 3PAO to analyze vulnerability scans. If the CSP successfully addresses the questions in the pre-assessment phase, then any findings or issues during the assessment phase should be easy to address. It is worth noting that Schellman takes a holistic approach to identifying and reporting vulnerabilities on the Risk Exposure Table (RET).  

In other words, if a particular vulnerability is reported on a specific host in the Scans of Record, but in the Remediation scans, a different host is flagged for the vulnerability instead, then that vulnerability would stay on the RET. This approach ensures that vulnerabilities are being remediated across the environment, despite the host.  

There are three main areas to tackle while reviewing the scan data in the assessment: 

• Current Picture: What vulnerabilities exist in the environment as of the current date? 
• Reassurance on Remediation: Are vulnerabilities continuing to be remediated in a timely manner? 
• Adjustments: What changes have been made since the pre-assessment? 

Of these three items, adjustments often have the biggest impact. Examples of adjustments that frequently occur and need to be addressed include: 

• If the vulnerability scanning tool has changed 
• If the scan checks have been modified 
• If the personnel responsible for configuring and running the scans are no longer with the organization 
• If the technologies within the environment have changed 
• If the environment hosting the solution has changed 

If any of these adjustments exist, the 3PAO will need to perform additional validation activities. 

Stage 3: Final Scan 

A final round of scans should be run by the CSP 30 days after their initial Scans of Record. At this point, all questions related to the personnel running the scans, the processes deployed, and the technologies implemented should be answered. The last set of scans should show evidence of remediation activities on the vulnerabilities identified in the assessment phase.  

There are three primary goals related to the last piece of scan evidence: 

• Remediation scans: Has a final set of scans that shows remediation of findings from the assessment phase been provided? 
• Operational Requirements (OR), Risk Adjustment (RA), and False Positives (FP): Are all ORs, RAs, and FPs documented in the Plan of Actions and Milestones (POA&M), reviewed and understood? 
• Ready for Continuous Monitoring: Are there any high severity findings remaining, and is the CSP ready to provide monthly results to an agency or the Joint Authorization Board (JAB)? 

High severity findings are highlighted due to their outsized impact on a FedRAMP ATO. Should any findings persist as of the date the SAR is issued, these findings should be tracked in the CSPs POA&M. 

Navigating FedRAMP Vulnerability Scanning with Confidence 

As of 2025, FedRAMP continues to place strong emphasis on authenticated scans, complete scan coverage, and timely remediation — all of which are critical to achieving and maintaining an ATO. For additional information on the requirements, timing, and handling of vulnerability scans, please see the following documents on the FedRAMP website: 

• FedRAMP Vulnerability Scanning Requirements 
• FedRAMP JAB P-ATO Process, Timeliness and Accuracy of Testing Requirements 

If you’re ready to begin your FedRAMP Assessment or have additional questions about the process or requirements, Schellman can help. Contact us today and we’ll get back to you shortly. In the meantime, discover other FedRAMP insights in these helpful resources:  

• FedRAMP 20x: Key Changes and Impacts to Cloud Service Providers 
• FedRAMP at a Crossroads: A “Lifetime” 3PAO’s Perspective 
• The FedRAMP Readiness Assessment Report (RAR) Requirements for CSPs