COORDINATION OF THREAT TO INTELLIGENCE COMMUNITY AUTOMATED INFORMATION SYSTEMS AND NETWORKS, 1988-89

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CIA-RDP90M00551R001800960020-5
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RIPPUB
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S
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21
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December 27, 2016
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July 22, 2013
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20
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Publication Date: 
October 27, 1988
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MEMO
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Declassified in Part- Sanitized Copy Approved forRelease2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 eSi& NATIONAL FOREIGN INTELLIGENCE BOARD /9-Zk .1 WASHINGTON, DC. 20505 NFIB 9.11/2 27 October 198 MEMORANDUM FOR NATIONAL FOREIGN INTELLIGENCE BOARD PRINCIPALS FROM: Executive Secretary SUBJECT: Coordination of Threat to Intelli ence Co 25X1 Information Systems and Networks, 19:8-8' OCT 19 WAD it STA mated The above-cited document (attached) is forwarded at the direction of Deputy Director of Central Intelligence Gates for your coordination. Please 25X1 provide any comments to and certify 25X1 your coordination to the Secretariat by noon on STAT 25X1 25X1 ' 25X1 10 November 1988. If the Secretariat has not heard received a request for more time for consideration, that you concur with the document as drafted. Attachment: As Stated from you by that time, or the Secretariat will take im Declassified in Part- Sanitized Copy Approved forRelease2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SUBJECT: Coordination of Threat to Intelligence Community Automated Information 25X1 Systems and Networks, 1988-89 Distribution: NFIB 9.11/2 Copy 1 - DCI 2 - DDCI 3 - Executive Registry 4 - DDI - DIRNSA 6 - D/DIA 7 - D/INR/State 8 - DoE 9 - FBI 10 - Treasury 11 - SAFSS 12 - Army DCSINT 13 - DNI 14 - Air Force ACSI 15 - USMC 16 - ES/NFIB 17 - NFIB Subject 18 - NFIB Chrono 19 - D/ICS - DD/ICS - DD/R&E/ICS 20 - ICS Registry 25X1 ES/NFIB, (27 Oct 88) Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 25X1 THREAT TO INTELLIGENCE COMMUNITY AUTOMATED INFORMATION SYSTEMS AND NETWORKS 1 988-1 989 SENIOR EXECUTIVE PANEL MEMBERSHIP (Alphabetical Listing): Baker, Dr. Lara H. Bayse, William A. Mr. Bush, Mr. James 0. Davis, Dr. Ruth M. Deskin, Mr. George W. Lockwood. Mr. Earl F. Los Alamos National Laboratory Federal Bureau of Investigation Planning Research Corporation The Pymatuning Group, Inc., Chairman Deskin Research Group National Security Agency Intelligence Community Staff Betac Corporation National Security Agency Central Intelligence Agency Defense Intelligence Agency THREAT TO INTELLIGENCE COMMUNITY AUTOMATED INFORMATION SYSTEMS AND NETWORKS 1988-1989 DRAFTING GROUP MEMBERSHIP (Alphabetical Listing): Baker, Dr. Lara ? Los Alamos National Laboratory 25X1 Central Intelligence Agency National Security Agency National Security Agency Defense Intelligence Agency 25X1 Special Agent Paul D. Federal Bureau of Investigation Hausman. Dr. Robert. Jr. Los Alamos National Laboratory 25X1 Intelligence Community Staff McNulty, Mr. Lynn Department of State 25X1 Central Intelligence Agency Schwalm, Mr. Roger US Secret Service 25X1 Central Intelligence Agency REGRADE AS CONFIDENTIAL WHEN SEPARATED FROM ATTACHMENT 25X1 SECRET IN= Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 SECRET DRAFT THREAT TO INTELLIGENCE COMMUNITY AUTOMATED INFORMATION SYSTEMS AND NETWORKS 1988-1989 WARNING: The contributing organizations view the contents of this document as extremely sensitive. A strict adherence to the need-to-know principle is required. This document, in part or in its entirety, is not releasable to foreign nationals. SECRET Fall 1988 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 25X1 25X1 25X1 25X1 25X1 25X1 DCI'S THREAT TO AUTOMATED INFORMATION SYSTEMS (AIS) AND NETWORKS 1988 SENIOR EXECUTIVE PANEL . Lara Baker Drafting Group Liaison Los Alamos National Laboratory 62izz_ Mr. William A. Bayse Assistant Director Technical Services Division Federal Bureau of Investigation James 0. Bush Vice President, Planning Emhart PRC .60t4 /74 Dr. Ruth M. Davis, Panel Chairman President The Pymatuning Group, Inc. . Ge)e*e W. Deskin air n of the Board Deskin Research Group ICS Liaison Intelli ence Community Staff Mr. Earl F. ockwood President and CEO Betac Corporation Chief, National Information Security Assessment Center National Security Agency Deputy Di-recior for Physical and Technical Security Office of Security Central Intelligence Agency Deputy Director for Information Systems Defense Intelligence Agency Director, National Comligteri-' Security Center 2 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 25X1 25X1 25X1 25X1 2bAl 25X1 PREFACE The Threat to Intelligence Community Automated Information Systems and Networks 1988-1989 addresses the threat to intelligence information through computers and networks of computers. This document provides a comprehensive treatment of the computer?related threat to classified and unclassified intelligence information and it includes the basic thinking and judgments that uide the Intelligence Community in understanding the threat to its systems. The Senior Executive Panel would like to acknowledge the efforts the following individuals who contributed to this report: of the Central Intelligence Agency (CIA), of the National Security Agency (NSA), of the Defense Intelligence Agency (DIA), Special Agent Paul D. FitzGerald of the Federal Bureau of Investigation, Dr. Robert F. Hausman, Jr., of Los Alamos National Laboratory, Mr. Lynn McNulty of the Department of State. IA, Mr. Roger Schwalm of the US Secret Service, of CIA, and of NSA. Government organizations and employees should consult the computer security element of their agencies for further information and guidance. Contractors and their employees should consult the appropriate g officers technical representative for further information. SECRET leo Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 R Next 86 Page(s) In Document Denied Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part- Sanitized Copy Approved forRelease2013/07/22 : CIA-RDP90M00551R001800960020-5 cFrPFT 25X1 25X1 ACCREDITATION APPENDIX A GLOSSARY Accreditation is the specific management authorization for operation of an AIS or network and is based on the certification process as well as on other management considerations. The accreditation statement affixes security responsibility with the accrediting authority and shows due care has been taken for security. By extension, it also covers AISs that are inter that participate cooperatively in a network. The formal declaration by a designated authority that an AIS or network is approved to operate (a) in a particular security mode, (b) with a prescribed set of technical and nontechnical security safeguards, (c) against a defined threat, (d) in a given operational environment, (e) under a stated operational concept, (f) with stated interconnections to other AISs or networks, (g) at an acceptable level of risk for which the accreditin authority has formally assumed responsibility. Systems processing intelligence will require a joint accreditation with an appropriate IC official when such systems are under the operational control of a US Government official not connected with the IC. AUTOMATIC DATA PROCESSING (ADP) SYSTEM The assembly of computer hardware, firmware, and software used to categorize, sort, calculate, compute, summarize, store, retrieve, control, process, and/er nrntr,t data with a minimum of human intervention. ADP systems include, but are not limited to, process control computers, embedded computer systems that perform general purpose computing functions, supercomputers, personal computers, intelligent terminals, word processors, office automation systems, firmware, and other implementations of AIS technologies as may be developed; they a application and operating system software. Qn SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 ASSOCIATED DATA COMMUNICATIONS Associated data communications play many roles for an AIS and for connections among multiple AISs. The simplest is that of connecting geographically nearby users (direct users) and geographically remote users (indirect users) to a stand- alone AIS, and also interconnecting various components (e.g., multiple host computers) of the central AIS equipment. Such associated data communications will be considered in the accreditation of the AISs using the requirements in Section III. Associated data communications also facilitate the interconnection of multiple AISs as part of a separately accredited network. In effect, such a separately accredited network (including local area networks ELANs]) provides specialized common-carrier data communications to a limited subscriber community. It may be of limited geographic extent (a LAN), of metropolitan area size (tens of kilometers), or wide area (hundreds of kilometers, national, worldwide). Separately accredited networks must provide for networ in the form of access safeguards and controls. Unless they have already been accredited as part of a national telecommunications network, associated data communications, which handle intelligence in unencrypted form, must be included in the accreditation of the AIS or network to which they are attached. In this context, associated data communications include items such as protected wire distribution systems, concentrators, multiplexors, and network access devices. AUTOMATED INFORMATION SYSTEM (AIS) An AIS is an assembly of computer hardware, software, and/or firmware configured to collect, create, communicate, compute, disseminate, process, store, or control data or information. An AIS will typically consist of automatic data processing (ADP) system hardware, operating system and applications software associated peripheral devices, and associated data. Examples include information storage and retrieval systems, personal computers (PCs) and workstations, office automation systems, and automated message processing systems (AMPS.) In addition, those supercomputers and process control systems (e.g., embedded computer systems) that perform general-purpose computing functions are included. 91 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 AUTOMATED INFORMATION SYSTEM SECURITY BOUNDARY OF AN AIS All security features needed to provide an acceptable level of protection for hardware; software; and classified, sensitive unclassified, or critical data, material, or processes in the system. It includes: o All hardware and software functions, characteristics, and features. o Operational procedures. o Accountability procedures. o Access controls at all computer facilities (including those housing mainframes, terminals, minicomputers, or microcomputers). o Management constraints. o Physical protection. o Control of compromising emanations (TEMPEST). o Personnel and communications security (COMSEC). o Other security disciplines. For the purpose of identifying the mode of operation of an AIS to be accredited, the AIS has a conceptual boundary that extends to all intended users of a system, both directly and indirectly connected, who receive output from the system without a manual security review by an appropriately cleared authority. The location of such a review is commonly referred to as "an air gap." The perimeter of the AIS, which encompasses all the components of the AIS to be accredited, excludes separately orks to which the AIS is connected. BOUNDARY OF A NETWORK 25X1 For purposes of identifying the mode of a network to be separately accredited (including a local area network,) the boundary of a network extends to (but does not include) the AISs or other se.arately accredited networks that attach thereto. 92 ELRLI Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 CERTIFICATION SECRET The comprehensive evaluation of the technical and nontechnical security features of an AIS or network and other safeguards, made as part of and in support of the accreditation process, that establishes the extent to which a particular design and im lementation meets a set of security requirements. COMMUNICATIONS SECURITY (COMSEC) The protection resulting from all measures designed to deny unauthorized persons information of value that might be derived from the possession and study of telecommunications, or to mislead unauthorized persons in their interpretation of the results of such possession and study. Communications security includes cryptosecurity, transmission security, emission security, and physical security of communi ? ions security materials and information. COMPUTER SECURITY (COMPUSEC) DATA INFORMATION 25X1 The protection resulting from all measures designed to prevent deliberate or inadvertent unauthorized access, disclosure, acquisition, manipulation, modification, or loss of information contained in a system. 1. A representation of facts, concepts, information, or instructions in a manner suitable for communication, interpretation, or processing by humans or by an AIS. 2. Information with a specific physical representation. Any communication or reception of knowledge such as facts, data, or opinions, including numerical, graphic, or narrative forms, whether oral or maintained in any medium, including computerized data bases, paper, microform, or magnetic tape. 93 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 25X1 INFORMATION SYSTEM The organized collection, processing, transmission, and dissemination of information in accordance ned procedures, whether automated or manual. INFORMATION SYSTEMS SECURITY NETWORK The protection afforded to information systems in order to preserve the availability, integrity, and confidentiality of the systems and information contained within the systems. Such protection is the application of the combination of all security disciplines that will, at a minimum, include COMSEC, TEMPEST, COMPUSEC, personnel security, industrial securit , resource protection, and physical security. A network comprises communications media and all attached components whose responsibility is the transfer of information among a collection of AISs or workstations. Network components include packet switches, front7ond computers, network and technical control devices. 25X1 25X1 25X1 94 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 R Next 28 Page(s) In Document Denied Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 LDeclassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 APPENDIX E THREATS TO COMPUTER NETWORKS The threats to a network define the misuses of the system stemming from user, operator, and maintenance activities that are executed either purposefully or accidentally to exploit network vulnerabilities. Network threats and vulnerabilities are discussed below. THREATS Network threats can be summarized into several generic classes as follows: o Leaks o Adulteration o Physical damage o Denial of service o Misuse of network connectivities (connectivity?related threats) The first class of threat, leaks, involves the compromise of sensitive information by delivering information into the hands of a person not authorized to receive it. The second, adulteration, involves injection of undesired material into a network to render information or network resources unusable for the intended purpose. The third, physical damage, involves accidental or deliberate physical damage resulting from accidents and improper operation, environmental phenomena, deterioration, or sabotage. The fourth, denial of service involves deliberate degrading of network system performance or even making a network temporarily unusable through modification of components, overloading, or crashing of the network. It also includes intentional disruption of information exchange between network components. Finally, the threat of misuse of network connectivities involves deliberate or accidental misuse of information and network resources made possible by connections to remote terminals or processes. This class is actually basic to the previous four classes of theaLtothe extent that connections are involved in carrying them out. 125 VCRET 25X1 25X1 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 201.3/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 The general threat categories may be further broken down into specific threats or means of attack. The list of possible attacks arising from the various classes of threat include both single computer and network attacks. Attacks common to both include: o Sabotage o Spoofing o Confusing o Hacking o Software implants o Hardware implants o Microcode implants Those attacks related primarily to networking and telecommunications include: o Jamming o Cryptanalysis o Passive monitoring (interception of plain text, traffic analysis, compromising emanations) o Tapping o Unauthorized connections (transactions, sessions) o Message diversion (misrouting) o System spillage o Changing address tables (message, session) o Aborting network security controls o Critical node failures o Sabotage of remote facilities VULNERABILITIES Vulnerabilities offer the opportunity for threats to be executed. Threats can only be carried out because hardware, software, or procedural deficiencies, i.e., vulnerabilities, make unauthorized accesses to network components possible. These vulnerabilities represent an inability of the network to restrict user, operator, and maintainer accesses to only those components necessary to satisfy their needs and responsibilities. There are two basic categories of vulnerabilities: o Vulnerabilities in the network hardware and software components that permit an attacker to successfully carry out a threat. o Unpredictable hardware failures (including protection mechanisms) and human operational failures that permit attacks to be conducted. Such vulnerabilities are never completely eliminated but can be reduced b f ult detection, isolation, and 25X1 automatic error recovery. In the first category, the vulnerabilities in the network components are fundamentally the access paths to system components that facilitate their misuse. They stem from design and implementation errors introduced during 25X1 126 ,77ZET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 25X1 system development and make the network susceptible to attack. Design and implementation errors include both missing and inadequate protection mechanisms for preventing unauthorized access of system components. For example, a design error would be the failure to include a protection mechanism in a network for preventing unauthorized access. An implementation defect would be the misinterpretation of a design specification that led to an operational malfunction and failure defect, eventually resulting unauthorized access and subsequent misuse of network resources. In the second category, hardware failures in protection mechanisms and related hardware elements are probably the most common. Access control mechanisms in the hardware can fail and support either accidental or deliberate attacks. Errors in communications devices may cause the misrouting of information and thereby support attacks. Thus, it is desirable to have fault detection, isolation, and automatic error recovery capabilities for components posing such vulnerabilities. While the threats may be identified and enumerated, the identification and characterization of the system penetration vulnerabilities that su ort successful attacks is a far more complex and difficult problem. CONNECTION VARIABLES Networks are inherently distributed, both functionally and geographically. They also range in complexity from the simplest networks in which two systems are connected with a pair of wires (i.e., a communications channel), to more complex connections involving message switches as well as communications channels, and finally to the situations whereby services are moved out of the network hosts and located in dedicated processors within the network. This distributed and complex nature of networks gives rise to many connectivity-related threats. Connectivity threats involve the misuse of network resources through network connections. A network connection may be defined in terms of the components, bandwidth, and services provided. Thus, a network connection between terminal-host, host-host, and terminal-terminal components, may accommodate a diverse array of data rates and data classifications/compartments (bandwidth), and provide numerous services such as virtual terminal, fine transfer, and electronic mail. When dealing with connectivity threats, it is useful to view the network as composed of a number of separate computer systems, interconnected by solely passive communications media. Threats relating to the passive communications media are considered to be outside the scope of this discussion; in particular the threats pertaining to hardware and software systems involved in providing end-to-end encryption. Also, if end-to-end encryption is used, all portions of the network protected by the encryption are treated as "passive communications media." Connectivity threats vary according to the characteristics described above, I. e., type of subscriber components connected to the network, the bandwidth involved, and the type of service provided by the network. For example, given several interconnected component hosts providing interprocess 197 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 communications service, connections may vary considerably in terms of bandwidth and associated threats. Thus, connection A between two multilevel secure (MLS) systems, has a bandwidth that is both high volume and supports multiple classifications/compartments. Connection B is a low-volume, single classification and compartment connection between an MLS system and a dedicated mode system. Without the proper access controls, accountability and audit trails, Connection B with the dedicated system poses a much greater threat of information loss than Connection A. However, if adequate controls are present in both, Connection A, with its broad bandwidth, is under greater threat of attack because of the potentiall?reater loss of information. 25X1 Specific examples are discussed below. 25X1 Components. 25X1 25X1 Network subscribers may include: o Remote users o Remote terminals o Remote personal computers o Remote networks o User hosts o User processes on a user host o Switchable terminals o Dial-up hosts o Network nodes o Gateways Generally, connections with remote networks, gateways, personal computers, and switchable terminals are under greater threat of attack because access here could initiate access in all the other networks/components to which they connect (cascade effect). 125X1 Bandwidth. Bandwidth, as used in this.report, refers to the level of connectivity with regard to data rate (bits per second) and data security level. Security level reflects both the classification level (Top Secret, Secret) and SCI access level (compartments), as-well as the number of classifications/compartments involved. The bandwidth of a connection may involve any combination of these two factors: high-volume, multilevel, multicompartmented use; or low-volume, single-level, single-compartmented use, and so forth. Generally, the threat of attack increases with volume and security level. A one-way, low-volume connection between a remote terminal and dedicated host is less subject to attack than a high-volume conduit between network hosts carrying multiple classifications and compartments of 25X1 information. 25X1 128 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 Services. Many networks provide some or all of the following services: o Virtual Terminal (Requires open/close connection)--In a virtual terminal connection a user already attached to the network connects to a host at some other point on the network. The user wishes to interact with the remote host in the same way as if he/she were attached directly to that host as a terminal. o File Transfer--In a file transfer connection, a user wishes to transfer information, usually in files (real or virtual), between separate hosts. o Electronic Mail--In mail, information is transferred between hosts, as in file transfer, but the user normally specifies a particular user or group of users on remote hosts without authenticating himself/herself on the remote hosts. The remote hosts have some mechanism for storing the mail until it is read by the users on the remote systems. o Message Routing/Dissemination--Requires no open/close connections. When describing connectivity threat scenarios, it is important to identif the subscriber components, bandwidth, and types of service involved. UNDERLYING PROBLEMS Because network connections involve the union of communications and autonomous computers, certain technical problems and inconsistencies may occur from their interactions. These technical problems include: o Inconsistency in the end-to-end use of naming parameters and conventions. o Inability to reliably synchronize security state information end-to-end. o Inconsistent security policy and protection mechanisms at various networked stations. o Inadequate end-to-end error detection, isolation, and recovery mechanisms. o Inconsistent auditing standards and tools for audit reduction. o Independence of resource management strategies end-to-end These underlying technical problems give threats addressed in subsequent paragraphs. 129 rise to the general connectivity SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 CONNECTIVITY THREAT SCENARIOS Basic Problem: User-Level Connections The basic connectivity threat occurs at the user level when a user seeks access via a session or dial-up to a network resource. Unless a network has global control over users, information leaks may arise due to the large number of persons operating from different terminal stations at different sites with different authorizations for different resources, each of which has different classifications and compartments. SECRET For example, a user/process on host A wishes to communicate with processes/users on host B. The user logs into host A at clearance level x and establishes a virtual terminal connection to host B. If the user logs into B at a higher level than accredited for on A, then information may appear on the user's terminal that is at a higher level than the terminal is cleared for. If the user logs into B at a lower level, unless host A and/or the network can be trusted not to copy host A internal information (including files) to host B, there ic potential for unauthorized disclosure of information to B from host A. Normally, most user-level access to the network must be through the operating system of the host on which the user is working. Thus it appears that host B must decide at what level to allow the user to log-in. If B permits the user to log-in at a lower level, then host A could be compromised. If B permits the user to log-in at a higher level, then B could be compromised. B must only permit the log-in at the same clearance level as the user currently has at A. Otherwise, there is the potential of copying information from the user's higher level terminal to the lower level processes on B. A, on the other hand, must trust B to operate correctly. Such a security level mismatch may go unrecognized because it is conducted over cryptographically secured communications lines. Host Connections to Network Connectivity threats also occur at the network level when unauthorized hosts are allowed to connect to the network, in violation of a networkwide security policy (this aspect is discussed under the following heading, Propagation of Local Risk). OR, when authorized connections are established between host systems at many security levels, increasing the risk of information leaks due to inadequate access and authentication mechanisms. For example, hosts that are multilevel secure to the highest level sensitivity of information carried on the network could be connected directly to the network. Other network hosts must have some mechanism for protecting the network from the host, usually in the form of a network interface unit. 130 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 25X1 25X1 25X1 25X1 Declassified in Part- Sanitized Copy Approved forRelease2013/07/22 : CIA-RDP90M00551R001800960020-5 rt. Kr I 25X1 Propagation of Local Risk Sometimes, an unevaluated host is connected to a trusted network; or operational needs of a system may lead to the accreditation of a system for multilevel operation that would not meet the requirements for the recommended class. This exposes all users of all other systems connected to the network to the additional risk. Misuse may occur if the connections are two?way, or if there is no manual review of transmissions. Nth Party Connectivities In a networking environment, in the case where a subscriber is a subnet or gateway host, the question of how far to extend the access controls becomes an Issue. Nth party threats involve unauthorized access to information and misuse of network resources since one site may operate on behalf of another, which itself is operating on behalf of yet another, but in all cases for some ancestral user who initiated the request. This may result in several conditions that render the access and authentication mechanisms inadequate and increase the risk of unauthorized information disclosure: o The identification of the original requesting device/person may be needed but no longer available, jeopardizing the network security policy. o Information that should be carried at each stage of the chained requests is omitted, which also jeopardizes the network security policy. At a minimum, each stage should know of the previous stage; at a maximum, a trail of all previous stages should be carried. Cascade Threat The cascade problem exists when an unauthorized user can take advantage of network connections to compromise information across a range of security levels that is greater than the accreditation ran 'e of any one of the component systems that he must defeat to do so. For example, consider two hosts, A and B. Host A processes Secret and Top Secret information, and all users are cleared to at least Secret. Host B processes Confidential and Secret information, and all users are cleared to at least Confidential. While the risk of compromise in both hosts is small enough to justify their use with two levels of information, the system as a whole has three levels of information, increasing the potential harm that could be caused by compromise. When they are connected so that Secret data can pass from one to the other, an unauthorized user could defeat the access make Top Secret information available at the Confidential level. 25X1 131 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 25X1 25X1 25X1 25X1 Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 SECRET 25X1 Remote Diagnostics Vendor-supplied software is often maintained using a remote diagnostic capability. By its very nature, a diagnostic capability must bypass all access controls to allow the maintenance personnel access to data and software not normally available to users. When such a capability is remote the potential for information leaks is even greater. Incompatibilities Very-low-level details may have to be considered to make network connections safe and preserve the existing security properties of each. For example, suppose two identical multilevel hosts #1 and #2 process Unclassified through Top Secret data and have two compartments A and.B. In System 1, bit 0, of the compartment field of the communications protocol represents compartment A and bit 1 represents compartment B, while in System 2 it is the other way around. Even though both systems are multilevel secure, when they are connected the data will not be protected unless the bit mapping is taken into account. Physical Damage/Denial of Service While these threats are generic classes in themselves, they relate to the distributed nature of networks and increase in importance as the network complexity increases. For example, remotely located connections may afford saboteurs the opportunity to vandalize a network with less chance of detection. If the vandalized resource is essential, such as a power supply, a network can be totally disabled. Or, if a network is functionally distributed, and perhaps draws on operational information collected automatically by remote sensors and relayed back, disruption of the vital connections initiates disruption in all the components that depend on it. The more complex the network and the more vital the interdependency of its components, the greater the threat of denial of service/operational failures related to connectivities. In fact, the easiest way to disable a network ma be to disrupt some component or some other network upon which it depends. Management Complexity As data, functionality, and control become increasingly distributed, management becomes more com lex. Loss of management control of data and resources may result. 25X1 132 SECRET Declassified in Part - Sanitized Copy Approved for Release 2013/07/22 : CIA-RDP90M00551R001800960020-5 25X1 25X1 25X1 25X1 25X1 25X1 25X1 25X1