Appendix A: Data-Level Protections and Modernization of Federal IT
The provision of appropriate protections begins with ensuring that foundational information security capabilities are in place. These capabilities should be implemented for all Federal IT systems; and any IT Modernization efforts should leverage the below principles as a core component of their upgrades. As agencies look to prioritize their modernization efforts, they are encouraged to focus first on deployment of these principles for high value assets.
High value assets (HVAs) are assets, Federal information systems, and data, for which the unauthorized access, use, disclosure, disruption, modification, or destruction could cause a significant impact to the United States’ national security interests, foreign relations, economy, or to the public confidence, civil liberties, or public health and safety of the American people. This definition is codified in OMB Memorandum M-17-09, Management of Federal High Value Assets. As such, the protection of HVAs should be among the highest priority cybersecurity activities for Federal agencies.
Multi-Factor Authentication. The goal of multi-factor authentication is to make remote attacks unattractive, typically by requiring the production of a credential that is specifically connected to a user in a physical manner in order to grant the user access to a system. Recent Federal efforts have focused on multi-factor authentication for privileged users, or those with elevated access privileges, but thus far has largely centered on network access rather than system and application-level access.
Least Privilege. The principle of least privilege states that users should only be granted access to the specific systems and information they need in order to execute their official duties. In practice, this is achieved by limiting administrative privileges. Mature privilege management programs may also be able to leverage policy- or attribute-based access controls, wherein sophisticated rules-based policies (which can be dynamically updated and enforced) can support a system that makes privilege escalation more expensive and difficult for an attacker.
Timely Patching. One of the most significant threats to IT systems remains unpatched software vulnerabilities. For that reason, OMB, under OMB Memorandum M-15-01, Fiscal Year 2014-2015 Guidance on Improving Federal Information Security and Privacy Management Practices, required agencies to sign memorandums of agreement or understanding to allow the DHS to scan their external-facing systems for unpatched vulnerabilities. Under Binding Operational Directive 15-01, DHS then required agencies to patch critical vulnerabilities within 30 days of being notified of such vulnerabilities. Agencies should prioritize the creation of routine, and ideally automated, patching processes for their HVAs that ensure that critical vulnerabilities are resolved much more rapidly than the required 30 days.
In addition to the above capabilities that all agencies are expected to adopt, there are numerous information security capabilities which agencies are advised to deploy pursuant to assessments of the risk posed to a certain system or set of information. In the context of HVAs, the systems and information are, by definition, highly sensitive and/or impactful. As such, agencies should seriously consider the value of these capabilities in terms of better defending their “crown jewels.”
Encrypting Data at Rest. Data at rest is data in a database or other storage areas, as opposed to in transit between systems. Encrypting that data makes it inaccessible should an attacker manage to make a physical copy of it. Effective encryption of data at rest requires sufficiently strong encryption keys with sufficient randomness in key generation.1
Encrypting Data in Transit. Encrypting data as it transits from one device or system component to another protects data from modification or interception from an attacker with a network vantage point. Network routes that transit data between information system components, or between information systems and their users, should generally be treated as untrusted, even within agency-operated networks. In general, though particularly for HVAs, systems should rely only on protocols that can safely “fail closed,” or default to denying network access, under attack scenarios. Examples include Secure Shell (SSH) or Hyper Text Transfer Protocol Secure (HTTPS).
Secure Application Development. Security must be a regular, ongoing part of the software development process, not simply a paperwork exercise completed prior to production deployment. Security teams should be integrated throughout the software development process, starting from its earliest stages. Such an approach can alleviate the characterization of security personnel as impediments, but, rather, as essential members of the larger development team.
Security Testing. Penetration testing, phishing tests, and database assessments should be incorporated into the testing regimen for agency HVAs. Agencies should establish a vulnerability disclosure policy for public-facing services so that security researchers and members of the public can report vulnerabilities they discover. Teams wishing to go further should consider running bug bounty programs, such as those run by the Department of Defense or GSA.
Threat Modeling. Engineering teams should use threat modeling to understand and drive improvements in the security of the HVA. Threat models help identify the most vulnerable parts of an application. This focuses resources in the areas where risk reduction is needed the most, and forms a cornerstone of implementing a risk-based practice of security like the NIST Cybersecurity Framework.
Application Whitelisting. The purpose of application whitelisting is to allow only approved applications and application components (libraries, configuration files, etc.) to run on a host according to a well-defined baseline, while preventing all other applications from running by default. When implemented, application whitelisting is an effective security technique that helps stop the execution of malicious malware and other unauthorized software.2
Mobile Device Management. Mobile devices often need additional protection because their nature generally places them at higher exposure to threats than other devices typically used within Government facilities, such as desktops and laptops. When planning mobile device security policies and controls, agencies should assume that mobile devices will be acquired by malicious parties who will attempt to recover sensitive data either directly from the devices themselves or indirectly by using the devices to access the organization’s remote resources. Therefore, a layered mitigation strategy should be used that includes user authentication to the device, protection of data either through encryption or by not storing data on the device, and user training and awareness to reduce the frequency of insecure physical security practices. Additionally, agencies should plan their mobile device security on the assumption that unknown third-party mobile device applications downloadable by users should not be trusted. Risk from these applications can be reduced in several ways, such as prohibiting all installation of third-party applications, implementing whitelisting to allow installation of approved applications only, verifying that applications only receive the necessary permissions on the mobile device, or implementing a secure sandbox/secure container that isolates the organization’s data and applications from all other data and applications on the mobile device.3
Leveraging Modern Deployment Solutions
In addition to the solutions described above, agencies should consider how best to take advantage of protections afforded by modern deployment patterns (e.g. “DevOps”) and cloud-based architectures in the defense of their HVAs.
Automated Deployments. System deployments should be automated to the greatest extent possible, removing the potential for errors caused by breakdowns in internal processes. To support this, configuration and environmental details that support system deployment should be versioned and managed similarly to the software that comprises the system itself. This practice is necessary to achieve long-term consistency among critical system components, maintain adequate patching, and update velocity.
Immutable Deployments. By building on automation, production environments should be designed so that components are not modified in place subsequent to being deployed. Modification should be technically constrained wherever possible; for example, deployed servers should not allow remote logins. By taking advantage of virtualized infrastructure, new deployments can create brand new instances of deployed system software and supporting components, rather than updating the existing environment in place. This approach allows system owners to design their security architecture and monitoring to treat any in-place modification as a potential attack, and to use more comprehensive technical constraints on modification that remove opportunities for attackers to persist in a deployed environment.