An adversary uses stolen hash values for a user's credentials (username and password) to access systems managed under the same credential framwork that leverage the Lan Man (LM) and/or NT Lan Man (NTLM) authentication protocols. When authenticating via LM or NTLM, the hashed credentials' associated plaintext credentials are not requried for successful authentication. Therefore, if an adversary can obtain the hashed credentials of a user, he can then pass these hash values to the server or service to authenticate without needing to brute-force the hashes to obtain their cleartext values. The adversary can then impersonate the user and laterally move within the network. This technique can be performed against any operating system which leverages the LM or NTLM protocols.
Likelihood Of Attack
The table(s) below shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
The adversary needs to first obtain the hashed credentials of a user, via the use of a tool, prior to executing this attack.
The victim system must allow Lan Man or NT Lan Man authentication.
Determine if Lan Man and NT Lan Man authentication is allowed on the server.
The adversary uses a third-party tool to obtain hashed credentials to execute the attack.
The table below specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Prevent the use of Lan Man and NT Lan Man authentication on severs and apply patch KB2871997 to Windows 7 and higher systems.
Monitor system and domain logs for abnormal credential access.
Leverage system penetration testing and other defense in depth methods to determine vulnerable systems within a domain.
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.
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Page Last Updated or Reviewed:
July 31, 2018