SACM Working Group H. Birkholz
Internet-Draft Fraunhofer SIT
Intended status: Informational J. Lu
Expires: September 22, 2016 Oracle Corporation
N. Cam-Winget
Cisco Systems
March 21, 2016

Secure Automation and Continuous Monitoring (SACM) Terminology


This memo documents terminology used in the documents produced by SACM (Security Automation and Continuous Monitoring).

Status of This Memo

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Table of Contents

1. Introduction

Our goal with this document is to improve our agreement on the terminology used in documents produced by the IETF Working Group for Security Automation and Continuous Monitoring. Agreeing on terminology should help reach consensus on which problems we’re trying to solve, and propose solutions and decide which ones to use.

2. Terms and Definitions

This section describes terms that have been defined by other RFC’s and defines new ones. The predefined terms will reference the RFC and where appropriate will be annotated with the specific context by which the term is used in SACM.

Defined by the ITU in [X.1252] as “a statement made by an entity without accompanying evidence of its validity”. In the context of SACM, an assertion is a collection result that includes metadata about the data source (and optionally a timestamp indicating the point in time the assertion was created at). The validity of an assertion cannot be verified.
Defined in [RFC5209] as “the process of collecting posture for a set of capabilities on the endpoint (e.g., host-based firewall) such that the appropriate validators may evaluate the posture against compliance policy.”
Within SACM the use of the term is expanded to support other uses of collected posture (e.g. reporting, network enforcement, vulnerability detection, license management). The phrase “set of capabilities on the endpoint” includes: hardware and software installed on the endpoint.”
Defined in [RFC4949] as “a system resource that is (a) required to be protected by an information system’s security policy, (b) intended to be protected by a countermeasure, or (c) required for a system’s mission”. In the scope of SACM, an asset can be composed of other assets. Examples of Assets include: Endpoints, Software, Guidance, or X.509 public key certificates. An asset is not necessarily owned by an organization.
Asset Management:
The process by which assets are provisioned, updated, maintained and deprecated.
Defined in [RFC5209] as “data element including any requisite meta-data describing an observed, expected, or the operational status of an endpoint feature (e.g., anti-virus software is currently in use).” If not indicated otherwise, attributes in SACM are represented and processed as attribute value pairs.
Defined in [RFC4949] as “the process of verifying a claim that a system entity or system resource has a certain attribute value.”
Defined in [RFC4949] as “an approval that is granted to a system entity to access a system resource.”
A broker is a specific controller type that contains control plane functions to provide and/or connect services on behalf of other SACM components via interfaces on the control plane. A broker may provide, for example, authorization services and find, upon request, SACM components providing requested services.
The extent of an SACM component’s ability enabled by the functions it is composed of. Capabilities are propagated by a SACM component and can be discovered by or negotiated with other SACM components. For example, the capability of a SACM Provider may be to provide endpoint management data, or only a subset of that data.
Collection Result:
Information about a target endpoint that is produced by a collector conducting a collection task. A collection result is composed of one or more endpoint attributes.
Collection Task:
The task by which endpoint attributes and/or corresponding attribute values about a target endpoint are collected. There are three types of collection tasks, each requiring an appropriate set of functions to be included in the SACM component conducting the collection task:
Self-Reporting: A SACM component located on the target endpoint itself conducts the collection task.
Remote-Acquisition: A SACM component located on an Endpoint different from the target endpoint conducts the collection task via interfaces available on the target endpoint, e.g. SNMP/NETCONF or WMI.
Behavior-Observation: A SACM component located on an Endpoint different from the target endpoint observes network traffic related to the target endpoint and conducts the collection task via interpretation of that network traffic.
A piece of software that acquires information about one or more target endpoints by conducting collection tasks. A collector provides acquired information to SACM components in the form of collection results. A SACM component that consumes collection results may take on the role of a provider and publish the collection results in a SACM domain. (TBD: A collector may not be a SACM component and therefore not part of a SACM domain).
A consumer is a SACM role that is assigned to a SACM component that contains functions to receive information from other SACM components.
Control Plane:
Typically used as a term in the context of routing, e.g. [RFC6192]. In the context of SACM, the control plane is an architectural component providing common control functions to all SACM components, including authentication, authorization, capability discovery or negotiation. The control plane orchestrates the flow on the data plane according to guidance and/or input from the management plane. SACM components with interfaces to the control plane have knowledge of the capabilities of other SACM components within a SACM domain.
A controller is a SACM role that is assigned to a SACM component containing control plane functions that manage and facilitate information sharing or execute on security functions. There are three types of SACM controllers: Broker, Proxy, and Repository. Depending on its type, a controller can also contain functions that have interfaces on the data plane.
Data Confidentiality:
Defined in [RFC4949] as “the property that data is not disclosed to system entities unless they have been authorized to know the data.”
Data Integrity:
Defined in [RFC4949] as “the property that data has not been changed, destroyed, or lost in an unauthorized or accidental manner.”
Data Origin:
One or more properties that enable a SACM component to identify the SACM component that initially acquired or produced data about a (target) endpoint (e.g. via collection from a data source).
Data Plane:
Typically used as a term in the context of routing (and used as a synonym for forwarding plane, e.g. [RFC6192]). In the context of SACM, the data plane is an architectural component providing operational functions to enable a SACM component to provide and consume SACM statements and therefore SACM content (the “payload”). The data plane is used to conduct distributed SACM tasks by transporting SACM content using transporting encodings and corresponding operations defined by SACM data models.
Data Provenance:
A historical record of the sources, origins and evolution of data that is influenced by inputs, entities, functions and processes.
Data Source:
One or more properties that enable a SACM component to identify an (target) endpoint that is claimed to be the original source of received data.
Defined in [RFC5209] as “any computing device that can be connected to a network. Such devices normally are associated with a particular link layer address before joining the network and potentially an IP address once on the network. This includes: laptops, desktops, servers, cell phones, or any device that may have an IP address.”
To further clarify the [RFC5209] definition, an endpoint is any physical or virtual device that may have a network address. Note that, network infrastructure devices (e.g. switches, routers, firewalls), which fit the definition, are also considered to be endpoints within this document.
The SACM architecture differentiates two essential categories of endpoints: Endpoints whose security posture is intended to be assessed (target endpoints) and endpoints that are specifically excluded from endpoint posture assessment (excluded endpoints).
Based on the definition of an asset, an endpoint is a type of asset.
Endpoint Attribute:
In the context of SACM, endpoint attributes are information elements that describe a characteristic of a target endpoint. Endpoint Attributes typically constitute atomic information elements (AVP) that can be bundled into composite information elements (e.g. information about a specific network interface can be represented via a set of multiple AVP).
Endpoint Characterization:
The task by which a profile is composed out of endpoint attributes that describe the desired or expected posture of a type or class of target endpoints or even an individual target endpoint. The result of this task is an endpoint profile that is required as guidance for the tasks of endpoint classification or posture assessment.
Endpoint Classification:
The task by which a discovered target endpoint is classified. Endpoint classification requires guidance in the form of an endpoint profile, discovery results and potentially collection results. Types, classes or the characteristics of an individual target endpoint are defined via endpoint profiles.
Evaluation Task:
The task by which endpoint attributes are evaluated.
Evaluation Result:
The resulting value from having evaluated a set of posture attributes.
Excluded Endpoint:
A specific designation, which is assigned to an endpoint that is not supposed to be the subject of a collection task (and therefore is not a target endpoint). Typically but not necessarily, endpoints that contain a SACM component (and are therefore part of the SACM domain) are designated as excluded endpoints. Target endpoints that contain a SACM component cannot be designated as excluded endpoints and are part of the SACM domain.
Expected Endpoint State:
The required state of an endpoint that is to be compared against. Sets of expected endpoint states are transported as guidance in target endpoint profiles via the management plane. This, for example, can be a policy, but also a recorded past state. An expected state is represented can be represented via a atomic information element or an composite information element that represents a set of multiple attribute value pairs.
SACM Function:
A behavioral aspect or capacity of a particular SACM component, which belies that SACM component’s purpose. For example, a SACM function with interfaces on the control plane can provide a brokering function to other SACM components. Via data plane interfaces, a function can act as a provider and/or as a consumer of information. SACM functions can be propagated as the capabilities of a SACM component and can be discovered by or negotiated with other SACM components.
Input to processes and tasks, such as collecting, assessing or reporting. Guidance influences the behavior of a SACM component and is considered content of the management plane. Guidance can be manually or automatically generated or provided. Typically, the tasks that provide guidance to SACM components have a low-frequency and tend to be be sporadic. A prominent example of guidance are target endpoint profiles, but guidance can have many forms, including:
Configuration, e.g. a SACM component’s name, or a CMDB’s IPv6 address.
Profiles, e.g. a set of expected states for network behavior associated with target endpoints employed by specific users.
Policies, e.g. an interval to refresh the registration of a SACM component, or a list of required capabilities for SACM components in a specific location.
Information Model:
An information model is an abstract representation of data, their properties, relationships between data and the operations that can be performed on the data. While there is some overlap with a data model, [RFC3444] distinguishes an information model as being protocol and implementation neutral whereas a data model would provide such details. The purpose of the SACM information model is to ensure interoperability between SACM data models (that are used as transport encoding) and to provide a standardized set of information elements for communication between SACM components.
Interaction Model:
For now this is a Place-Holder. Is an interaction model that defines, for example, the operations on the control plane, such as registration or SACM component discovery, required?
Internal Collector:
Internal Collector: a collector that runs on a target endpoint to acquire information from that target endpoint. (TBD: An internal collector is not a SACM component and therefore not part of a SACM domain).
Management Plane:
An architectural component providing common functions to steer the behavior of SACM components, e.g. its behavior on the control plane. Prominent examples include: modification of the configuration of a SACM component or updating a target endpoint profile that resides on an evaluator. In essence, guidance is transported via the management plane. Typically, a SACM component can fulfill its purpose without continuous input from the management plane. In contrast, without continuous availability of control plane functions a typical SACM component could not function properly. In general, interaction on the management plane is less frequent and less regular than on the control plane. Input via the management plane can be manual (e.g. via a CLI), or can be automated via management plane functions that are part of other SACM components.
Network Address:
Network addresses are layer specific and follow layer specific address schemes. Each interface of a specific layer can be associated with one or more addresses appropriate for that layer. There is no guarantee that an address is globally unique. In general, there is a scope to an address in which it is intended to be unique.
Examples include: physical Ethernet port with a MAC address, layer 2 VLAN interface with a MAC address, layer 3 interface with multiple IPv6 addresses, layer 3 tunnel ingress or egress with an IPv4 address.
Network Interface:
An endpoint is connected to a network via one or more interfaces. Interfaces can be physical or virtual. Interfaces of an endpoint can operate on different layers, most prominently what is now commonly called layer 2 and 3. Within a layer, interfaces can be nested. On layer 2, a root interface is typically associated with a physical interface port and nested interfaces are virtual interfaces. In the case of a virtual endpoint, a root interface can be a virtual interface. Virtual layer 2 interfaces of one or more endpoints can also constitute an aggregated group of links that act as one. On layer 3, nested interfaces typically constitute virtual tunnels or networks.
Examples include: physical Ethernet port, layer 2 VLAN interface, a MC-LAG setup, layer 3 Point-to-Point tunnel ingress or egress.
Defined in [RFC5209] as “configuration and/or status of hardware or software on an endpoint as it pertains to an organization’s security policy.”
This term is used within the scope of SACM to represent the configuration and state information that is collected from a target endpoint in the form of endpoint attributes (e.g. software/hardware inventory, configuration settings, dynamically assigned addresses). This information may constitute one or more posture attributes.
Posture Attributes:
Defined in [RFC5209] as “attributes describing the configuration or status (posture) of a feature of the endpoint. A Posture Attribute represents a single property of an observed state. For example, a Posture Attribute might describe the version of the operating system installed on the system.”
Within this document this term represents a specific assertion about endpoint configuration or state (e.g. configuration setting, installed software, hardware) represented via endpoint attributes. The phrase “features of the endpoint” highlighted above refers to installed software or software components.
A provider is a SACM role that is assigned to a SACM component that contains functions to provide information to other SACM components.
A proxy is a specific controller type that provides data plane and control plane functions, information, or services on behalf of another component, which is not directly participating in the SACM architecture.
A repository is a specific controller type that contains functions to consume, store and provide information of a particular kind - typically data transported on the data plane, but potentially also data and metadata from the control and management plane. A single repository may provide the functions of more than one specific repository type (i.e. configuration baseline repository, assessment results repository, etc.)
SACM Role:
SACM roles are associated with SACM components and are defined by the set of functions and interfaces a SACM component includes. There are three SACM roles: provider, consumer, and controller. The roles associated with a SACM component are determined by the purpose of the functions and corresponding interfaces the SACM component is composed of.
SACM Component:
A set of SACM functions composes a SACM component. A SACM component conducts SACM tasks, acting on control plane, data plane and/or management plane via corresponding SACM interfaces. SACM defines a set of standard components (e.g. a collector, a broker, or a data store). A SACM component contains at least a basic set of control plane functions and can contain data plane and management plane functions. A SACM component residing on an endpoint assigns one or more SACM roles to the corresponding endpoint due to the SACM functions it is composed of. A SACM component “resides on” an endpoint and an endpoint “contains” a SACM component, correspondingly. For example, a SACM component that is composed solely of functions that provide information would only take on the role of a provider.
SACM Component Discovery:
The function by which a SACM component (e.g. by role, capabilities, or data provided/consumed) can be discovered.
SACM Domain:
Endpoints that include a SACM component compose a SACM domain. (To be revised, additional definition content TBD, possible dependencies to SACM architecture)
Security Automation:
The process of which security alerts can be automated through the use of different tools to monitor, evaluate and analyze endpoint and network traffic for the purposes of detecting misconfigurations, misbehaviors or threats.
Software Package:
A generic software package (e.g. a text editor).
Software Component:
A software package installed on an endpoint, including a unique serial number if present (e.g. a text editor associated with a unique license key).
Software Instance:
A running instance of the software component (e.g. on a multi-user system, one logged-in user has one instance of a text editor running and another logged-in user has another instance of the same text editor running, or on a single-user system, a user could have multiple independent instances of the same text editor running).
The output of a provider, e.g. a report or an assertion acquired via a collection result from a collector, that includes metadata about the data origin and the point in time the statement was created at. A statement can be accompanied by evidence of the validity of its metadata.
The entity seeking to be authenticated by the Management Plane for the purpose of participating in the SACM architecture.
System Resource:
Defined in [RFC4949] as “data contained in an information system; or a service provided by a system; or a system capacity, such as processing power or communication bandwidth; or an item of system equipment (i.e., hardware, firmware, software, or documentation); or a facility that houses system operations and equipment.
Target Endpoint:
A target endpoint is an “endpoint under assessment” (even if it is not actively under assessment at all times) or “endpoint of interest”. Every endpoint that is not specifically designated as an excluded endpoint is a target endpoint. A target endpoint is not part of a SACM domain unless it contains a SACM component (e.g. a SACM component that publishes collection results coming from an internal collector).
A target endpoint is similar to a device that is a Target of Evaluation (TOE) as defined in Common Criteria.
Target Endpoint Discovery:
The function by which target endpoints can be discovered. The output of target endpoint discovery typically includes identifying endpoint attributes.
Target Endpoint Identifier:
The target endpoint discovery process and collection tasks targeted at target endpoints can result in a set of identifying endpoint attributes. This set of identifying endpoint attributes is used as a target endpoint identifier referring to a specific target endpoint. Depending on the available identifying attributes this reference can be ambiguous and is a “best-effort” mechanism. Every distinct set of identifying endpoint attributes can be associated with a unique target endpoint label.
Target Endpoint Label:
An artificially created id that references a distinct set of identifying attributes (Target Endpoint Identifier). A target endpoint label is unique in a SACM domain and created by a SACM component that contains an appropriate function.
Target Endpoint Profile:
A bundle of expected or desired configurations and states (typically a composition of endpoint attribute value pairs) that can be associated with a target endpoint. The corresponding task by which the association with a target endpoint takes places is the endpoint classification. The task by which a endpoint profile is created is the endpoint characterization. A type or class of target endpoints is defined within a target endpoint profile, e.g. printer, smartphone, or an office PC.
(SACM) Task:
[TBD conflicts in definitions of specific tasks] A SACM task is conducted by one or more SACM functions that reside on a SACM component (e.g. a collection task or endpoint characterization). A SACM task can be triggered by other operations or functions (e.g. a query from another SACM component or an unsolicited push due to a subscription on the data plane). A task is part of a SACM process chain. A task starts at a given point in time and ends in a deterministic state. With the exception of a collection task, a SACM task consumes SACM content. The output of a task is a result that can be provided (e.g. published) on the data plane. There are six fundamental tasks defined in SACM:
Asset Classification: Map the assets on the target endpoints to asset classes. This enables identification of the attributes needed to exchange information pertaining to the target endpoint. [the label now conflicts with Endpoint Classification]
Attribute Definition: Define the attributes desired to be collected from each target endpoint. This is what we want to know about a target endpoint. For instance, organizations will want to know what software is installed and its many critical security attributes such as patch level.
Policy Definition: This is where an organization can express its policy for acceptable or problematic values of an endpoint attribute. The expected values of an endpoint attribute are determined for later comparison against the actual endpoint attribute values during the evaluation process. Expected values may include both those values which are good as well as those values which represent problems, such as vulnerabilities. The organization can also specify the endpoint attributes that are to be present for a given target endpoint.
Information Collection: Collect information (attribute values) from the target endpoint to populate the endpoint data.
Endpoint Assessment: Evaluate the actual values of the endpoint attributes against those expressed in the policy. (An evaluation result may become additional endpoint data).
Result Reporting: Report the results of the evaluation for use by other components. Examples of use of a report would be additional evaluation, network enforcement, vulnerability detection, and license management.
Timestamps :
Defined in [RFC4949] as “with respect to a data object, a label or marking in which is recorded the time (time of day or other instant of elapsed time) at which the label or marking was affixed to the data object” and as “with respect to a recorded network event, a data field in which is recorded the time (time of day or other instant of elapsed time) at which the event took place.”.
This term is used in SACM to describe a recorded point in time at which an endpoint attribute is created or updated by a target endpoint and observed, transmitted or processed by a SACM component. Timestamps can be created by target endpoints or SACM components and are associated with endpoint attributes provided or consumed by SACM components. Outside of the domain of SACM components the assurance of correctness of time stamps is typically significantly lower than inside a SACM domain. In general, it cannot be simply assumed that the source of time a target endpoint uses is synchronized or trustworthy.

3. IANA Considerations

This memo includes no request to IANA.

4. Security Considerations

This memo documents terminology for security automation. While it is about security, it does not affect security.

5. Acknowledgements

6. Change Log

Changes from version 00 to version 01:

Changes from version 01 to version 02:

Changes from version 02 to version 03:

Changes from version 03 to version 04:

Changes from version 04 to version 05:

Changes from version 05 to version 06:

Changes from version 06 to version 07:

Changes from version 07 to version 08:

Changes from version 08 to version 09:

7. Contributors

David Waltermire
National Institute of Standards and Technology
100 Bureau Drive
Gaithersburg, MD  20877


Adam W. Montville
Center for Internet Security
31 Tech Valley Drive
East Greenbush, NY  12061


David Harrington
Effective Software
50 Harding Rd
Portsmouth, NH  03801


Nancy Cam-Winget
Cisco Systems
3550 Cisco Way
San Jose, CA  95134


Jarrett Lu
Oracle Corporation
4180 Network Circle
Santa Clara, CA  95054


Brian Ford
3650 Brookside Parkway, Suite 500
Alpharetta, GA  30022


Merike Kaeo
Double Shot Security
3518 Fremont Avenue North, Suite 363
Seattle, WA  98103


8. Informative References

, "
[RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between Information Models and Data Models", RFC 3444, DOI 10.17487/RFC3444, January 2003.
[RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007.
[RFC5209] Sangster, P., Khosravi, H., Mani, M., Narayan, K. and J. Tardo, "Network Endpoint Assessment (NEA): Overview and Requirements", RFC 5209, DOI 10.17487/RFC5209, June 2008.
[RFC6192] Dugal, D., Pignataro, C. and R. Dunn, Protecting the Router Control Plane", RFC 6192, DOI 10.17487/RFC6192, March 2011.
[X.1252]ITU-T X.1252 (04/2010)", n.d..

Appendix A. The Attic

The following terms are stashed for now and will be updated later:

Asset Characterization:
Asset characterization is the process of defining attributes that describe properties of an identified asset.
Asset Targeting:
Asset targeting is the use of asset identification and categorization information to drive human-directed, automated decision making for data collection and analysis in support of endpoint posture assessment.
An architectural component receiving services from another architectural component.
Endpoint Identification (TBD per list; was “Endpoint Discovery”):
The process by which an endpoint can be identified.

Authors' Addresses

Henk Birkholz Fraunhofer SIT Rheinstrasse 75 Darmstadt, 64295 Germany EMail:
Jarrett Lu Oracle Corporation 4180 Network Circle Santa Clara, CA 95054 USA EMail:
Nancy Cam-Winget Cisco Systems 3550 Cisco Way San Jose, CA 95134 USA EMail: