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This blog post is also authored by Forrest Shull.

Modern software systems are constantly exposed to attacks from adversaries that, if successful, could prevent a system from functioning as intended or could result in exposure of confidential information. Accounts of credit card theft and other types of security breaches concerning a broad range of cyber-physical systems, transportation systems, self-driving cars, and so on, appear almost daily in the news. Building any public-facing system clearly demands a systematic approach for analyzing security needs and documenting mitigating requirements. In this blog post, which was excerpted from a recently published technical report, we present the Hybrid Threat Modeling Method that our team of researchers developed after examining popular methods.

Cost estimation was cited by the Government Accountability Office (GAO) as one of the top two reasons why DoD programs continue to have cost overruns. How can we better estimate and manage the cost of systems that are increasingly software intensive? To contain costs, it is essential to understand the factors that drive costs and which ones can be controlled. Although we understand the relationships between certain factors, we do not yet separate the causal influences from non-causal statistical correlations. In this blog post, we explore how the use of an approach known as causal learning can help the DoD identify factors that actually cause software costs to soar and therefore provide more reliable guidance as to how to intervene to better control costs.

When considering best practices in egress filtering, it is important to remember that egress filtering is not focused on protecting your network, but rather on protecting other organizations' networks. For example, the May 2017 Wannacry Ransomware attack is believed to have exploited an exposed vulnerability in the server message block (SMB) protocol and was rapidly spread via communications over port 445. Egress and ingress filtering of port 445 would have helped limit the spread of Wannacry. In this post--a companion piece to Best Practices for Network Border Protection, which highlighted best practices for filtering inbound traffic--I explore best practices and considerations for egress filtering.

Almost 30 years ago, the SEI's CERT Coordination Center established a program that enabled security researchers in the field to report vulnerabilities they found in an organization's software or systems. But this capability did not always include vulnerabilities found on Department of Defense (DoD) sites. In 2017, the SEI helped expand vulnerability reporting to the DoD by establishing the DoD Vulnerability Disclosure program. This blog post, which was adapted from an article in the recently published 2017 Year in Review, highlights our work on this program.

This post is co-authored by Thomas Scanlon.

When a private key in a public-key infrastructure (PKI) environment is lost or stolen, compromised end-entity certificates can be used to impersonate a principal (a singular and identifiable logical or physical entity, person, machine, server, or device) that is associated with it. An end-entity certificate is one that does not have certification authority to authorize other certificates. Consequently, the scope of a compromise or loss of an end-entity private key is limited to only those certificates whose keys were lost.

Since it is the certificate that provides the identity used for authorization, authentication of a compromised certificate can lead to critical consequences, such as loss of proprietary data or exposure of sensitive information. Compromised certificates can be used as client-authentication certificates in SSL to authenticate principals associated with the certificate (e.g., a principal mapped in Active Directory, LDAP, or another database) or they may be accepted as is, depending on the service. This blog post describes strategies for how to recover and minimize consequences from the loss or compromise of an end-entity private key.

As detailed in last week's post, SEI researchers recently identified a collection of vulnerabilities and risks faced by organizations moving data and applications to the cloud. In this blog post, we outline best practices that organizations should use to address the vulnerabilities and risks in moving applications and data to cloud services.

These practices are geared toward small and medium-sized organizations; however, all organizations, independent of size, can use these practices to improve the security of their cloud usage. It is important to note that these best practices are not complete and should be complemented with practices provided by cloud service providers, general best cybersecurity practices, regulatory compliance requirements, and practices defined by cloud trade associations, such as the Cloud Security Alliance.

As we stressed in our previous post, organizations must perform due diligence before moving data or applications to the cloud. Cloud service providers (CSPs) use a shared responsibility model for security. The CSP accepts responsibility for some aspects of security. Other aspects of security are shared between the CSP and the consumer or remain the sole responsibility of the consumer.

This post details four important practices, and specific actions, that organizations can use to feel secure in the cloud.

Organizations continue to develop new applications in or migrate existing applications to cloud-based services. The federal government recently made cloud-adoption a central tenet of its IT modernization strategy. An organization that adopts cloud technologies and/or chooses cloud service providers (CSP)s and services or applications without becoming fully informed of the risks involved exposes itself to a myriad of commercial, financial, technical, legal, and compliance risks. In this blog post, we outline 12 risks, threats, and vulnerabilities that organizations face when moving application or data to the cloud. In our follow-up post, Best Practices for Cloud Security, we explore a series of best practices aimed at helping organizations securely move data and applications to the cloud.