Detecting and preventing privilege escalation attacks leveraging Kerberos relaying (KrbRelayUp)

 Post from Microsoft

On April 24, 2022, a privilege escalation hacking tool, KrbRelayUp, was publicly disclosed on GitHub by security researcher Mor Davidovich. KrbRelayUp is a wrapper that can streamline the use of some features in Rubeus, KrbRelay, SCMUACBypass, PowerMad/SharpMad, Whisker, and ADCSPwn tools in attacks.

Although this attack won’t function for Azure Active Directory (Azure AD) joined devices, hybrid joined devices with on-premises domain controllers remain vulnerable. Microsoft Defender for Identity detects activity from the early stages of the attack chain by monitoring anomalous behavior as seen by the domain controller. In addition, signals from Defender for Identity also feed into Microsoft 365 Defender, providing organizations with a comprehensive solution that detects and blocks suspicious network activities, malicious files, and other related components of this attack. Microsoft Defender Antivirus detects this attack tool as the malware family HackTool:MSIL/KrbUpRly.

Microsoft encourages customers to update Domain Controller: LDAP server signing requirements to Require signing as detailed in this advisory and enable Extended Protection for Authentication (EPA) as detailed in this blog.

Originally, KrbRelayUp supported only one method that’s based on taking advantage of resource-based constrained delegation (RBCD); it later added several additional attack methods. In this blog, we discuss RBCD to provide further insights into how the initial KrbRelayUp attack method works. We also detail the stages that make up the said attack. Finally, we provide recommendations and guidelines that can help organizations strengthen their device configurations and defend their networks from attacks that use this tool.

Understanding the attack: What is resource-based constrained delegation?

Resource-based constrained delegation (RBCD) represents the key to this attack method, enabling the tool to impersonate an administrator and eventually run a code as the SYSTEM account of a compromised device.

Authentication protocol basics

An authentication protocol verifies the legitimacy of a resource or identity. When a user signs into a website, that website uses a methodology to confirm the authenticity of the resource requesting access. In simpler terms, the authentication process involves signing in with a password—made possible by the user knowing the password anticipated by the website. The Kerberos protocol serves as the main authentication framework for this process in on-premises Active Directory.


Sometimes, however, a resource needs to request access to another resource on behalf of a different identity. A common example of this is mail delegation, wherein executives often give delegation rights to their executive assistants to send and receive emails on their behalf without providing the assistant with the executive’s password. The executive assistant isn’t authenticating as the executive; the executive has just allowed the assistant’s account to “pretend” that they are.

Resource-based constrained delegation

Initially, only users with the SeEnableDelegation role could configure delegation, typically domain admins. These domain admins can manage resources and dictate which identities can act on behalf of a different resource. They achieve this by updating the msDS-AllowedToDelegateTo property of a user account or device. This property contains a list of all the unique identifiers (service principal names, or SPNs) to which this object can delegate or act on behalf of.

However, as organizations expanded, administrators struggled to manage all the delegation requirements, raising the need for a new type of delegation: resource-based. For instance, in an organization with several file servers that all trust a web server for delegation, an admin would have to change the msDS-AllowedToDelegateTo priority in all of the different file servers to introduce a second web server. With resource-based delegation, the list of trusted computers is held on the receiving end. Thus, in our example, only the newly created server would require a change of settings.

To read the rest of this article and find the steps you can use to defend go Here

Blockchain for Access Control Systems: NIST IR 8403

NIST has published NIST
Internal Report (NIST IR) 8403, Blockchain for
Access Control Systems
. Protecting system resources
against unauthorized access is the primary objective of an access control
system. As information systems rapidly evolve, the need for advanced access
control mechanisms that support decentralization, scalability, and trust – all
major challenges for traditional mechanisms – has grown.

Blockchain technology offers high confidence and tamper resistance
implemented in a distributed fashion without a central authority, which means
that it can be a trustable alternative for enforcing access control policies.
This document presents analyses of blockchain access control systems from the
perspectives of properties, components, architectures, and model supports, as
well as discussions on considerations for implementation.


Emergency Directive and Releases Advisory Related to VMware Vulnerabilities

 CISA has issued Emergency
Directive (ED) 22-03
 and released a Cybersecurity Advisory
 in response to active and expected exploitation of multiple
vulnerabilities in the following VMware products: VMware Workspace ONE Access
(Access), VMware Identity Manager (vIDM), VMware vRealize Automation (vRA),
VMware Cloud Foundation, vRealize Suite Lifecycle Manager.

The CSA, AA22-138B:
Threat Actors Chaining Unpatched VMware Vulnerabilities for Full System Control
provides indicators of compromise and detection signatures from CISA as well as
trusted third parties to assist administrators with detecting and responding to
active exploitation of CVE-2022-22954 and CVE-2022-22960.  Malicious cyber
actors were able to reverse engineer the vendor updates to develop an exploit
within 48 hours and quickly began exploiting these disclosed vulnerabilities in
unpatched devices. Based on this activity, CISA expects malicious cyber actors
to quickly develop a capability to exploit CVE-2022-22972 and CVE-2022-22973,
which were disclosed by VMware on May 18, 2022. 

ED 22-03 directs
all Federal Civilian Executive Branch agencies to enumerate all instances of
affected VMware products and either deploy updates provided in VMware
Security Advisory VMSA-2022-0014
, released May 18, 2022, or remove those
instances from agency networks.

CISA strongly encourages all organizations to deploy updates provided in VMware
Security Advisory VMSA-2022-0014
 or remove those instances from
networks. CISA also encourages organizations with affected VMware products that
are accessible from the internet to assume compromise and initiate threat
hunting activities using the detection methods provided in the CSA. If
potential compromise is detected, administrators should apply the incident
response recommendations included in the CSA.

Potential security vulnerabilities have been identified in the BIOS (UEFI Firmware) for certain HP PC products


A vulnerability has been
discovered in certain HP PC BIOS, which could allow for local arbitrary
code execution. The BIOS is a firmware which is used to provide runtime services
for operating systems and programs and to perform hardware initialization
during the booting process. Successful exploitation of this vulnerability
could allow for local arbitrary code execution with kernel level
privileges. An attacker could then install programs; view, change, or
delete data; or create new accounts with full user rights.


Threat Intelligence

A proof-of-concept writeup was
posted to GitHub on May 10, 2022
. However, there are no reports of active exploitation
of the vulnerability.


System Affected
This vulnerability is found in the BIOS of numerous HP systems. For a full
list of affected systems and BIOS versions, please click here:



– Large and medium government

– Small government entities: High



– Large and medium business
– Small business entities: High


Home Users: Low


Technical Summary

This vulnerability is exploited by
taking advantage of System Management Interrupt Handler (SMI Handler)’s
functionality to execute code from overwritten memory. The CVEs associated
with this vulnerability are: CVE-2021-3808 and CVE-2021-3809.



We recommend the following
actions be taken:


  • Upgrade to
    the latest version of the BIOS for systems affected.
  • Run all
    software as a non-privileged user (one without administrative
    privileges) to diminish the effects of a successful attack.


Cryptographic Module Validation Program Security Policy Requirements: Draft Revision of NIST Special Publication 800-140B

The initial public draft of NIST Special Publication (SP)
800-140Br1 (Revision 1),
CMVP Security Policy Requirements: CMVP Validation Authority
Updates to ISO/IEC 24759 and ISO/IEC 19790 Annex B
, is now
available for public comment. This draft introduces four significant changes to
NIST SP 800-140B:

  1. Defines a more detailed
    structure and organization for the Security Policy
  2. Captures Security Policy
    requirements that are defined outside of ISO/IEC 19790 and ISO/IEC 24759
  3. Builds the Security Policy
    document as a combination of the subsection information
  4. Generates the approved
    algorithm table based on lab/vendor selections from the algorithm tests

The NIST SP 800-140x series supports Federal Information
Processing Standards (FIPS) Publication 140-3, Security Requirements for Cryptographic Modules,
and its associated validation testing program, the Cryptographic Module
Validation Program (CMVP). The series specifies modifications to ISO/IEC 19790
Annexes and ISO/IEC 24759 as permitted by the validation authority.

The public comment period for this initial public draft is open
through July 12, 2022.
See the publication
for instructions on submitting comments.


NIST Publishes Review of Digital Forensic Methods


The National Institute of Standards and Technology (NIST) has published Digital Investigation Techniques: A NIST Scientific Foundation Review. This draft report, which will be open for public comment for 60 days, reviews the methods that digital forensic experts use to analyze evidence from computers, mobile phones and other electronic devices.

The purpose of NIST scientific foundation reviews is to document and evaluate the scientific basis for forensic methods. These reviews fill a need identified in a landmark 2009 studyby the National Academy of Sciences, which found that many forensic disciplines lack a solid foundation in scientific research.

To conduct their review, the authors examined peer-reviewed literature, documentation from software developers, test results on forensic tools, standards and best practices documents and other sources of information. They found that “digital evidence examination rests on a firm foundation based in computer science,” and that “the ap plication of these computer science techniques to digital investigations is sound.”

“Copying data, searching for text strings, finding timestamps on files, reading call logs on a phone. These are basic elements of a digital investigation,” said Barbara Guttman, leader of NIST’s digital forensics research program and an author of the study. “And they all rely on fundamental computer operations that are widely used and well understood.”

The report also discusses several challenges that digital forensic experts face, including the rapid pace of technological change. “Digital evidence techniques don’t work perfectly in all cases,” Guttman said. “If everyone starts using a new app, forensic tools won’t be able to read and understand the contents of that app until they are updated. This requires constant effort.”

To address this challenge, the report recommends better methods for information-sharing among experts and a more structured approach to testing forensic tools that would increase efficiency and reduce duplication of effort across labs.

The report also recommends increased sharing of high-quality forensic reference data that can be used for education, training, and developing and testing new forensic tools.

NIST’s Digital Forensics Research Program, which was launched in 1999, develops methods for testing digital forensics tools and provides access to high-quality reference datasets. NIST also maintains a vast archive of published software, the National Software Reference Library, that is a critical resource for investigating computer crimes.

NIST scientific foundation reviews help laboratories identify appropriate limitations on the use of forensic methods, identify priorities for future research, and suggest steps for moving the field forward. These reviews are conducted as part of NIST’s Forensic Science Program, which works to strengthen forensic practice through research and improved standards. In 2018 Congress directed NIST to conduct these scientific reviews and appropriated funding for them.

Readers can submit comments on the draft report through July 11, 2022. NIST will host a webinar about the draft report on June 1, 2022. Instructions for submitting comments and registration information for the webinar are available on the NIST website.

Protecting Against Cyber Threats to Managed Service Providers and their Customers

The cybersecurity authorities of the United Kingdom (NCSC�UK), Australia (ACSC), Canada (CCCS), New Zealand
(NCSC-NZ), and the United States (CISA), (NSA), (FBI) are
aware of recent reports that observe an increase in
malicious cyber activity targeting managed service providers
(MSPs) and expect this trend to continue.[1] This joint
Cybersecurity Advisory (CSA) provides actions MSPs and
their customers can take to reduce their risk of falling victim
to a cyber intrusion.
This advisory describes cybersecurity best practices for
information and communications technology (ICT) services
and functions, focusing on guidance that enables
transparent discussions between MSPs and their customers
on securing sensitive data. 

Organizations should implement
these guidelines as appropriate to their unique
environments, in accordance with their specific security
needs, and in compliance with applicable regulations. MSP
customers should verify that the contractual arrangements with their provider include cybersecurity
measures in line with their particular security requirements. 

The guidance provided in this advisory is specifically tailored for both MSPs and their customers and
is the result of a collaborative effort from the United Kingdom National Cyber Security Centre (NCSUK), the Australian Cyber Security Centre (ACSC), the Canadian Centre for Cyber Security (CCCS),
the New Zealand National Cyber Security Centre (NCSC-NZ), the United States’ Cybersecurity and
Infrastructure Security Agency (CISA), National Security Agency (NSA), and Federal Bureau of
Investigation (FBI) with contributions from industry members of the Joint Cyber Defense Collaborative (JCDC). Organizations should read this advisory in conjunction with NCSC-UK guidance on actions to
take when the cyber threat is heightened, CCCS guidance on Cyber Security Considerations for
Consumers of Managed Services, and CISA guidance provided on the Shields Up and Shields Up
Technical Guidance webpages.

To read the full details go HERE

Blockchain and Related Technologies to Support Manufacturing Supply Chain Traceability: Needs and Industry Perspectives (NISTIR 8419)

The NIST National Cybersecurity Center of Excellence (NCCoE) has
published NIST Internal Report (NISTIR) 8419, Blockchain and Related Technologies to Support
Manufacturing Supply Chain Traceability: Needs and Industry Perspectives


Supply chains are increasingly complex, making the origins of
products difficult to discern. Efforts are emerging to increase traceability of
goods by exchanging traceability data records using blockchain and related
technologies among relevant supply chain participants.

NISTIR 8419 explores the issues that surround traceability,
the role that blockchain and related technologies may be able to play to
improve traceability, and several industry case studies of efforts in use


The publication covers:

  • existing factors that inhibit
    manufacturing supply chain traceability
  • analysis of emerging
    blockchain-enabled manufacturing supply chain traceability initiatives in
  • recommendations for future
    research topics to improve manufacturing supply chain traceability,
    enabled by blockchain and related technologies

If you have questions, or would like to join the NCCoE Blockchain
Project Community of Interest, email:

the Document