NIST revises guidance for telework security
Agency continues development of IT security configuration scoring system
- By William Jackson
- Jun 17, 2009
Teleworking and remote access to network resources present security challenges, and the National Institute of Standards and Technology has revised its guidance for addressing those concerns.
“The nature of telework and remote access technologies — permitting access to protected resources from external networks, and often external hosts as well — generally places them at higher risk than similar technologies only accessed from inside the organization, as well as increasing the risk to the internal resources made available to teleworkers through remote access,” states Revision 1 of NIST’s Special Publication 800-46, "Guide to Enterprise Telework and Remote Access Security."
The guidance, first published in 2002, is intended to help organizations understand and mitigate the risks of teleworking by emphasizing the importance of securing sensitive information stored on telework devices and transmitted across external networks. It also provides recommendations for selecting, implementing and maintaining the necessary security controls.
NIST calls the revised guidance a comprehensive update to the original publication.
“Major security concerns include the lack of physical security controls, the use of unsecured networks, the connection of infected devices to internal networks, and the availability of internal resources to external hosts,” the guidelines state. “This publication provides information on security considerations for several types of remote access solutions, and it makes recommendations for securing a variety of telework and remote access technologies. It also gives advice on creating telework security policies.”
NIST’s recommendations for securing telework and remote access technologies include:
- Plan telework security policies and controls based on the assumption that external environments contain hostile threats. Solutions include encryption and not storing data on remote clients.
- Develop a telework security policy that defines telework and remote access requirements.
- Ensure that remote access servers are secured effectively and configured to enforce telework security policies and prevent remote connections from becoming jumping-off points for attacks on other network resources. Keeping servers patched is crucial, and administrators should consider having a single point of entry to the network.
- Secure telework client devices against common threats and maintain their security regularly.
IT security scoring system coming into focus
NIST is also continuing work on a system for scoring information technology security configurations and has released a second draft of Interagency Report 7502, "The Common Configuration Scoring System: Metrics for Software Security Configuration Vulnerabilities," for comment.
The Common Configuration Scoring System (CCSS) is a system of standardized measurements to evaluate the impact of security configurations on operating systems and applications.
“Each security configuration decision can have positive and negative effects of varying degrees to the security of a host,” the draft document states. “Without a standardized way to quantify these effects, organizations cannot easily make sound decisions as to how each security issue should be addressed, nor can they quantitatively determine the overall security strength or weakness for a host.”
CCSS is derived from the Common Vulnerability Scoring System, which was developed to measure the severity of vulnerabilities that result from software flaws. CCSS is intended to assist in making decisions on how to address security configuration issues and can provide data for quantitative assessments of a system’s overall security posture. The report defines proposed measures for CCSS and equations for combining the measures into severity scores for each configuration issue. It also provides examples of how to determine CCSS measures and scores for a diverse set of security configuration issues.
An initial draft of the report was released for comment a year ago. Comments on the current draft should be sent by July 17 to IR7502comments@nist.gov, with “Comments IR 7502” in the subject line.
William Jackson is a Maryland-based freelance writer.