Network Endpoint Assessment
|Document||Charter||Network Endpoint Assessment WG (nea)|
|Title||Network Endpoint Assessment|
|IESG||Responsible AD||Stephen Farrell|
|Charter edit AD||(None)|
|Send notices to||(None)|
Network Endpoint Assessment (NEA) architectures have been implemented in the industry to assess the "posture" of endpoint devices for the purposes of monitoring compliance to an organization's posture policy and optionally restricting access until the endpoint has been updated to satisfy the posture requirements. An endpoint that does not comply with posture policy may be vulnerable to a number of known threats that may exist on the network. The intent of NEA is to facilitate corrective actions to address these known vulnerabilities before a host is exposed to potential attack. Note that an endpoint that is deemed compliant may still be vulnerable to threats that may exist on the network. The network may thus continue to be exposed to such threats as well as the range of other threats not addressed by maintaining endpoint compliance. Posture refers to the hardware or software configuration of an endpoint as it pertains to an organization's security policy. Posture may include knowledge that software installed to protect the machine (e.g. patch management software, anti-virus software, host firewall software, host intrusion protection software or any custom software) is enabled and up-to-date. An endpoint supporting NEA protocols can be queried for posture information. An organization may make a range of policy decisions based on the posture of an endpoint. NEA is not intended to be prescriptive in this regard. Supported deployment scenarios will include, but are not limited to, providing normal access regardless of compliance result along with any recommendations for remediation ("advisory mode"), as well as providing restricted access sufficient for remediation purposes and any essential services until an endpoint is in compliance ("mandatory mode"). Specifying mechanisms for providing restricted access is outside the scope of the NEA WG. Since NEA involves many different components from different vendors, interoperability is important. The NEA working group will develop standard protocols at the following three layers in the architecture: the Posture Attribute protocol (PA), the Posture Broker protocol (PB), and the Posture Transport protocol (PT). PA and PB will be designed to support a variety of PT protocols. Together, PA, PB and the mandatory to implement PT protocols will allow interoperability between an NEA Client from one vendor and an NEA Server from another. Since there are already several non-standard protocols at these layers, the NEA working group will consider these existing protocols as candidates for the standard protocols. A requirements document will be written and used as a basis for evaluating the candidate protocols. The working group may decide to standardize one of the candidate protocols, use one of them as a basis for a new or revised protocol, or decide that a new protocol is needed. The NEA Requirements document will include a problem statement, definition of terms, requirements for the PA and PB protocols, and an overall security analysis. It will also include generic requirements for the protocol transporting PA, PB: the Posture Transport protocol (PT). The PA (Posture Attribute) protocol consists of posture attributes that are carried between a particular Posture Collector in a NEA client and a particular Posture Validator in a NEA Server. The PA protocol is carried inside the PB protocol. A base set of standard posture attributes will be specified that are expected to address many common posture policies. Vendor-specific attributes will also be supported; vendor-specific attributes will be identified by a private enterprise number and a vendor assigned value. Vendors are strongly encouraged to document vendor-specific attributes in an RFC. The NEA WG will investigate the use of a standard syntax for all attributes. The PB (Posture Broker) protocol aggregates posture attributes from one or more Posture Collectors in an NEA client and sends them to the NEA server for assessment by one or more Posture Validators. The PT (Posture Transport) protocol carries the PB protocol. The expectation is that the PT protocol is a shim protocol that defines an encapsulation of PB within an existing standard transport protocol. Existing standard transport protocols will be leveraged to the extent possible. The NEA WG may specify more than one PT to meet the requirements of different deployment scenarios. The NEA WG will specify at least one mandatory to implement PT protocol. PT protocol specifications must describe any limitations that they impose on PB and PA (e.g. half duplex). One commonly discussed issue with NEA systems is how to handle compromised endpoints, whose reports of their own posture may not be accurate. Detecting or handling such endpoints is out of scope of the NEA WG. Work on PA will focus on attributes useful for assessing posture of those endpoints reporting accurate information. However, the protocols developed by the NEA WG must be designed to accommodate emerging technologies for identifying and dealing with lying endpoints. Note that NEA is not chartered to develop standard protocols for remediation. NEA is intended to be used with new or existing tools that can be used in the absence of NEA. NEA is applicable to computing enterprise environments, where endpoints accessing the enterprise's network are owned and/or expected to conform to the policies set forth by the organization that owns and operates the network. All other cases are outside the scope of the NEA charter, since we do not know that NEA would be useful in such cases. NEA applicability and security considerations will be described in the appropriate NEA documents. Further work in the NEA WG will be considered via the rechartering process after the completion of these milestones.