NSA, CISA release Kubernetes Hardening Guidance

The National Security Agency (NSA) and the Cybersecurity and Infrastructure Security Agency (CISA) released a Cybersecurity Technical Report, “Kubernetes Hardening Guidance,”. This report details threats to Kubernetes environments and provides configuration guidance to minimize risk.
Kubernetes is an open source system that automates the deployment, scaling, and management of applications run in containers. Kubernetes clusters are often hosted in a cloud environment, and provide increased flexibility from traditional software platforms.
Kubernetes is commonly targeted for three reasons: data theft, computational power theft, or denial of service. Data theft is traditionally the primary motivation; however, cyber actors may attempt to use Kubernetes to harness a network’s underlying infrastructure for computational power for purposes such as cryptocurrency mining.
The report details recommendations to harden Kubernetes systems. Primary actions include the scanning of containers and Pods for vulnerabilities or misconfigurations, running containers and Pods with the least privileges possible, and using network separation, firewalls, strong authentication, and log auditing.
To ensure the security of applications, system administrators should follow the guidance in the Cybersecurity Technical Report and keep up to date with patches, updates, and upgrades to minimize risk. NSA and CISA also recommend periodic reviews of Kubernetes settings and vulnerability scans to ensure appropriate risks are accounted for and security patches are applied.
NSA and CISA’s guidance focuses on security challenges and recommends system administrators harden their environments where possible. NSA is releasing this guidance as part of our mission to support the Department of Defense, the Defense Industrial Base, and National Security Systems.

NSA, CISA, and FBI detail Chinese State-Sponsored Actions, Mitigations

The National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA) and Federal Bureau of Investigation (FBI) released a Cybersecurity Advisory, Chinese State-Sponsored Cyber Operations: Observed TTPs. This advisory describes over 50 tactics, techniques, and procedures (TTPs) Chinese state-sponsored cyber actors used when targeting U.S. and allied networks, and details mitigations.
Chinese state-sponsored cyber activity poses a major threat to U.S. and allied systems. These actors aggressively target political, economic, military, educational, and critical infrastructure personnel and organizations to access valuable, sensitive data. These cyber operations support China’s long-term economic and military objectives.
One significant tactic detailed in the advisory includes the exploitation of public vulnerabilities within days of their public disclosure, often in major applications, such as Pulse Secure, Apache, F5 Big-IP, and Microsoft products. This advisory provides specific mitigations for detailed tactics and techniques aligned to the recently released, NSA-funded MITRE D3FEND framework.
General mitigations outlined include: prompt patching; enhanced monitoring of network traffic, email, and endpoint systems; and the use of protection capabilities, such as an antivirus and strong authentication, to stop malicious activity.

NSA Releases Guidance on Securing Unified Communications and Voice and Video over IP Systems

NSA released a Cybersecurity Technical Report that provides best practices and mitigations for securing Unified Communications (UC) and Voice and Video over IP (VVoIP) call-processing systems. The comprehensive report, “Deploying Secure Unified Communications/Voice and Video over IP Systems,” also describes potential risks to UC/VVoIP systems that aren’t properly secured.
To complement the larger report, NSA published an abridged Cybersecurity Information Sheet to capture key takeways and introduce the steps organizations should take when securing their UC/VVoIP systems.
UC and VVoIP are workplace call-processing systems that provide a variety of collaboration tools as well as the flexibility to communicate using voice, video conferencing and instant messaging. The access to advanced call-processing features and centralization of management have made UC and VVoIP popular in enterprise environments, including National Security System, Department of Defense and Defense Industrial Base networks.
The IP infrastructure that enables UC/VVoIP systems also presents risks that were less prevalent in the prior generation of call centers. If UC/VVoIP systems are not properly secured, they are susceptible to the same malicious activity targeting existing IP systems through spyware, viruses, software vulnerabilities or other malicious means. Malicious actors could penetrate the IP networks to eavesdrop on conversations, impersonate users, commit toll fraud and perpetrate denial of service attacks. High-definition room audio and video could also be covertly collected.
To securely deploy UC/VVOIP systems, NSA provides best practices to use when preparing networks, establishing network perimeters, using enterprise session controllers and adding endpoints to deploy a UC/VVOIP system.
Methods to minimize the risk to UC/VVOIP systems include segmenting the networks to limit access to a common set of devices, ensuring timely patching, authentication and encryption of all signaling and media traffic, and verifying the security of devices before adding them to a network.

NSA Funds Development, Release of D3FEND

D3FEND, a framework for cybersecurity professionals to tailor defenses against specific cyber threats is now available through MITRE.  NSA funded MITRE’s research for D3FEND to improve the cybersecurity of National Security Systems, the Department of Defense, and the Defense Industrial Base. The D3FEND technical knowledge base of defensive countermeasures for common offensive techniques is complementary to MITRE’s ATT&CK, a knowledge base of cyber adversary behavior.
D3FEND establishes terminology of computer network defensive techniques and illuminates previously-unspecified relationships between defensive and offensive methods. This framework illustrates the complex interplay between computer network architectures, threats, and cyber countermeasures.
MITRE released D3FEND as a complement to its existing ATT&CK framework, a free, globally-accessible knowledge base of cyber adversary tactics and techniques based on real-world observations. Industry and government use ATT&CK as a foundation to develop specific cyber threat models and methodologies.
Complementary to the threat-based ATT&CK model, D3FEND provides a model of ways to counter common offensive techniques, enumerating how defensive techniques impact an actor’s ability to succeed. By framing computer network defender complexity of countermeasure functions and techniques as granularly as ATT&CK frames computer network attacker techniques, D3FEND enables cybersecurity professionals to tailor defenses against specific cyber threats, thereby reducing a system’s potential attack surface. As a result, D3FEND will drive more effective design, deployment, and defense of networked systems writ large.
Frameworks such as ATT&CK and D3FEND provide mission-agnostic tools for industry and government to conduct analyses and communicate findings. Whether categorizing adversary behavior or detailing how defensive capabilities mitigate threats, frameworks provide common descriptions that empower information sharing and operational collaboration for an ever-evolving cyber landscape.

Joint NSA and CISA Guidance on Strengthening Cyber Defense Through Protective DNS

The National Security Agency (NSA) and CISA have released a Joint Cybersecurity Information (CSI) sheet with guidance on selecting a protective Domain Name System (PDNS) service as a key defense against malicious cyber activity. Protective DNS can greatly reduce the effectiveness of ransomware, phishing, botnet, and malware campaigns by blocking known-malicious domains. Additionally organizations can use DNS query logs for incident response and threat hunting activities.
CISA encourages users and administrators to consider the benefits of using a protective DNS service and review NSA and CISA’s CSI sheet on Selecting a Protective DNS Service for more information.
Protecting users’ DNS queries is a key defense because cyber threat actors use domain names across the network exploitation lifecycle: users frequently mistype domain names while attempting to navigate to a known-good website and unintentionally go to a malicious one instead (T1583.001); threat actors lace phishing emails with malicious links (T1566.002); a compromised device may seek commands from a remote command and control server (TA0011); a threat actor may exfiltrate data from a compromised device to a remote host (TA0010).1 The domain names associated with malicious content are often known or knowable, and preventing their resolution protects individual users and the enterprise.
Due to the centrality of DNS for cybersecurity, the Department of Defense (DoD) included DNS filtering as a requirement in its Cybersecurity Maturity Model Certification (CMMC) standard (SC.3.192). The Cybersecurity and Infrastructure Security Agency issued a memo and directive requiring U.S. government organizations to take steps to mitigate related DNS issues. Additionally, the National Security Agency has published guidance documents on defending DNS [1, 2, 3].
This guidance outlines the benefits and risks of using a protective DNS service and assesses several commercial PDNS providers based on reported capabilities. The assessment is meant to serve as information for organizations, not as recommendations for provider selection. Users of these services must evaluate their architectures and specific needs when choosing a service for PDNS and then validate that a provider meets those needs.

GCHQ and NSA Celebrate 75 Years of Partnership

The United Kingdom Government Communications Headquarters (GCHQ) and the United States National Security Agency (NSA) commemorate their partnership to share intelligence. These intelligence agencies have worked together for nearly a century to strengthen national security. March 5, 2021 marks the 75th anniversary of the formalized agreement to share information between the two agencies as much as possible, with minimal restrictions.
The British USA (BRUSA) Communications Intelligence (COMINT) Agreement, signed on March 5, 1946, was the original document that formalized the relationship. The agreement emerged from U.K. and U.S. specialists recognizing the beneficial results of intelligence sharing during World War II. The BRUSA Agreement was updated and expanded to become the UKUSA Agreement in 1955. This groundbreaking document created the policies and procedures for U.K. and U.S. intelligence professionals for sharing communication, translation, analysis, and code breaking information.
GCHQ and NSA personnel have worked together to address threats across all domains. The diversity of our experts provides better outcomes in analysis and innovative approaches to form solutions.
The UKUSA Agreement became the foundation for our intelligence alliances with Australia, Canada, and New Zealand. When the challenge is global, working with partners around the world is essential. This extraordinary trust and collaboration brings a strategic advantage in our nations’ safety.
The 75th anniversary of the UKUSA Agreement marks the passage of a historic and lasting relationship which enhances the resilience of our nations’ defenses and security of our future.

NSA releases “Eliminating Obsolete Transport Layer Security (TLS) Protocol Configurations” Cybersecurity Information

The National Security Agency released a cybersecurity product Tuesday detailing how to detect and fix out-of-date encryption protocol implementations. Networks and systems that use deprecated forms of Transport Layer Security (TLS) or Secure Sockets Layer (SSL) for traffic sessions are at risk of sensitive data exposure and decryption.
The Cybersecurity Information Sheet, “Eliminating Obsolete Transport Layer Security (TLS) Protocol Configurations” instructs National Security System (NSS), Department of Defense (DoD), and Defense Industrial Base (DIB) system administrators on how to detect, prioritize, and replace unauthorized or deprecated TLS protocols with ones that meet current standards. Committee on National Security Systems (CNSS) Policy 15 requires that TLS protocols used by National Security Systems meet specified algorithm standards. Remediation is crucial to decreasing computer system and network attack surfaces and preventing unauthorized access to private data.
To help system administrators fix their network components, NSA developed several server configurations and network signatures to accompany the report that are available on the NSA Cybersecurity Github. While this information is provided to assist NSA's mission customers, any network administrator interested in finding and fixing their network components to allow only authorized and strong encryption protocol configurations may find it useful.
NSA seeks to regularly release unique, actionable, and timely cybersecurity guidance to secure the Department of Defense, National Security Systems, and the Defense Industrial Base. For more information or other cybersecurity products, visit NSA.gov/cybersecurity-guidance.

NSA Cybersecurity Advisory: Malicious Actors Abuse Authentication Mechanisms to Access Cloud Resources

In response to ongoing cybersecurity events, the National Security Agency (NSA) released a Cybersecurity Advisory Thursday “Detecting Abuse of Authentication Mechanisms.” This advisory provides guidance to National Security System (NSS), Department of Defense (DoD), and Defense Industrial Base (DIB) network administrators to detect and mitigate against malicious cyber actors who are manipulating trust in federated authentication environments to access protected data in the cloud. It builds on the guidance shared in the cybersecurity advisory regarding VMware with state-sponsored actors exploiting CVE 2020-4006 and forging credentials to access protected files, though other nation states and cyber criminals may use this tactic, technique, and procedure (TTP) as well.
This advisory specifically discusses detection and mitigation of two TTPs to forge authentications and gain access to a victim’s cloud resources. While these TTPs require the actors to already have privileged access in an on-premises environment, they are still dangerous as they can be combined with other vulnerabilities to gain initial access, then undermine trust, security, and authentication. Initial access can be established through a number of means, including known and unknown vulnerabilities. The recent SolarWinds Orion ® code compromise is one serious example of how on-premises systems can be compromised, leading to abuse of federated authentication and malicious cloud access.
Mitigation actions include hardening and monitoring systems that run local identity and federation services, locking down tenant single sign-on (SSO) configuration in the cloud, and monitoring for indicators of compromise. NSA remains committed to providing provide timely, actionable and relevant guidance, and is partnering across the public and private sectors in ongoing incident response efforts. Releasing this advisory with further technical guidance allows NSA’s customers to apply preventative measures to the fullest extent along with the detection and mitigation actions.
Malicious cyber actors are abusing trust in federated authentication environments to access protected data. An “on premises” federated identity provider or single sign-on (SSO) system lets an organization use the authentication systems they already own (e.g. tokens, authentication apps, one-time passwords, etc.) to grant access to resources, including resources in “off premises” cloud services. These systems often use cryptographically signed automated messages called “assertions” shared via Security Assertion Markup Language (SAML) to show that users have been authenticated. When an actor can subvert authentication mechanisms, they can gain illicit access to a wide range of an organizations assets.
In some cases, actors have stolen keys from the SSO system that allow them to sign assertions and impersonate any legitimate user who could be authenticated by the system. On 7 December, NSA reported on an example where a zeroday vulnerability was being used to compromise VMware Access®1 and VMware Identity Manager®2 servers, allowing actors to forge authentication assertions and thus gain access to the victim’s protected data. In other cases, actors have gained enough privileges to create their own keys and identities such as “service principals” (cloud applications that act on behalf of a user) or even their own fake SSO system. According to public reporting, in some cases, the SolarWinds Orion code compromise provided actors initial access to an on-premises network which led to access within the cloud.
Note that these techniques alone do not constitute vulnerabilities in the design principles of federated identity management, the SAML protocol, or on-premises and cloud identity services. The security of identity federation in any cloud environment directly depends on trust in the on-premises components that perform authentication, assign privileges, and sign SAML tokens. If any of these components is compromised, then the trust in the federated identity system can be abused for unauthorized access.
To defend against these techniques, organizations should pay careful attention to locking down SSO configuration and service principal usage, as well as hardening the systems that run on-premises identity and federation services.
Monitoring the use of SSO tokens and the use of service principals in the cloud can help detect the compromise of identity services. While these techniques apply to all cloud environments that support on-premises federated authentication, the following specific mitigations are focused on Microsoft Azure federation. Many of the techniques can be generalized to other environments as well.