Local Area Networks (LANs) in Aircraft - FTP Directory Listing - FAA

More documents

Recommendations

Info

issues need to be agreed upon by the aeronautical community before airborne avionics systems become networked to other aircraft or ground systems. This is because the safety of networked airborne LAN systems is potentially affected by the quality and integrity of the network system that is created by the worldwide civil aviation community. It is risky to permit networked airborne LAN systems to be created before the worldwide civil aviation community has decided on a common approach to address these key subsystems. Aircraft need to handle identity, IP addressing, naming, routing, protocol security, and authentication in a consistent manner with each other and with civil aviation ground systems if aircraft and NAS systems are to be networked together. The interfaces of both airborne and ground systems, therefore, need to be carefully articulated and designed if potentially significant security problems are to be avoided. 7.2 EXTENDING DO-178B INTO NETWORKED ENVIRONMENTS. The system should identify the security and, thereby, the safety-related requirements for software. Software and system verification should ensure that they were correctly and completely implemented. The primary difference of extending software assurance processes into networked environments is to try to ensure that software vulnerabilities that can be attacked in networked environments do not exist. Latent bugs in software can be located in either the operating system, the application, or both. Of the five respondents to the FAA LAN survey (see appendix B) who identified which operating system hosted their airborne application, three did not use any OS at all, one used a COTS operating system, and one used a high-assurance OS. While any latent software bug is a potential avenue of attack, not all software bugs have equal exploitative potential. The vulnerabilities that exist within applications that are not built upon an OS are a function of that specific application environment itself and the ability of the attacker to compromise or modify that environment. By contrast, root kits are available on the Internet for exploiting generic COTS OSs (e.g., Windows ® , Apple Mac OS, Unix, etc.). These root kits often contain script-based attacks against the commonly known vulnerabilities of those systems with the goal to compromise the OS, deploy Trojan horses (for continued control), erase log files, and to launch attacks on other entities. Section 4.3 discussed the dangers associated with using COTS OSs. For these reasons, COTS OSs should not be deployed within high-assurance environments except via a HAG. By contrast, high-assurance OSs are an excellent choice for high-assurance airborne network environments. If a high-assurance OS contains any vulnerabilities at all, those vulnerabilities are esoteric. The DO-178B processes used to develop software targeted for networked airborne deployments need to be extended to explicitly reduce or eliminate the number of software vulnerabilities that can be leveraged by network-based attacks. However, as Ghosh, O’Connor, and McGraw have observed, processes alone cannot guarantee the creation of high-quality software: “Process maturity models and formally verified protocols play a necessary and important role in developing secure systems. It is important to note, however, that even the most rigorous processes can produce poor quality software. Likewise, even the most rigorously and formally analyzed protocol specification can be poorly implemented. In practice, market pressures tend to dominate the engineering and development of software, often at the expense of formal verification and even testing activities. … The result is a software product 96
employed in security-critical applications … whose behavioral attributes in relationship to security are largely unknown.” [95] Despite this, a variety of previous studies have proposed process extensions (e.g., references 40, 41, 73-75, and 95-97) using automated testing mechanisms at various stages of the development process to identify security vulnerabilities within software targeted for network environments. This study concurs with those studies that development processes need to include tests that examine the actual implemented product to verify that its development processes did indeed produce the expected results. Various mechanisms to improve the current process have been proposed including: • Using of model checkers on abstractions derived automatically from source code [40]. • Software fault injection into software to force anomalous program states during software execution and observing their corresponding effects on system security [95]. • Since a certain class of exploits relies upon buffer overflow vulnerabilities, various studies [96] have also recommended specific development mechanisms and tools for reducing that vulnerability during software development. Each of these approaches has a certain amount of overhead that may or may not be acceptable given specific implementation requirements. Regardless, these ideas nevertheless point out the desirability of understanding the root cause of the specific vulnerability and taking steps to correct it. However, while these additional tests are helpful, they cannot ensure that the resulting software is of a high quality. Tests only identify the presence of specific problems. Software testing alone cannot guarantee the absence of flaws that were not addressed by the test suite. Creating test suites to address all of the possible flaws that may exist in airborne software is an unachievable goal due to the myriad of potential problems that may arise. The goals of software testing should be solely viewed as “The approach described in this paper does not purport to find the needle in the haystack, but rather to reduce the size of the haystack significantly …” [95] There is no existing security theory or process that can extend testing systems to produce guaranteed high-assurance results for networked environments. This is a significant certification issue. Until this key missing certification element has been fixed, no networked system can currently be guaranteed to be as safe as nonnetworked airborne systems. Fortunately, this problem is partially mitigated by having code inspection be a constituent part of the certification process for higher assurance software (e.g., see DO-178B, Section 6.3.4 and Table A-5). In conclusion, this study recommends that the FAA study the viability of enhancing current DO-178B processes with the specific process extensions and tests suggested by previous studies [40, 41, 73-75, and 95-98]. 97
Page 1 and 2:
DOT/FAA/AR-08/31 Air Traffic Organi
Page 3 and 4:
1. Report No. DOT/FAA/AR-08/31 4. T
Page 5 and 6:
5.4.2 Aircraft as a Node (MIP and M
Page 7 and 8:
11.1 Findings and Recommendations 1
Page 9 and 10:
22 Customer’s L3VPN Protocol Stac
Page 11 and 12:
LIST OF ACRONYMS AND ABBREVIATIONS
Page 13 and 14:
PBN PC PE PEP PFS PIB PIM-DM PIM-SM
Page 15 and 16:
This report states that the primary
Page 17 and 18:
1. INTRODUCTION. This is the final
Page 19 and 20:
protocol (IP)-based communications.
Page 21 and 22:
of linking aircraft-resident system
Page 23 and 24:
Industry and governments are extrem
Page 25 and 26:
2.1 NOTIONAL NETWORKED AIRCRAFT ARC
Page 27 and 28:
Other Control Sites Controller ATC
Page 29 and 30:
• The security viability of curre
Page 31 and 32:
alternative requires that parallel
Page 33 and 34:
Aircraft network security is a syst
Page 35 and 36:
4. NETWORK RISKS. This section spec
Page 37 and 38:
General Threat Identifiers FAILURE
Page 39 and 40:
esources so that the required real-
Page 41 and 42:
“With the rise of client-side att
Page 43 and 44:
• During an 11-month period (Apri
Page 45 and 46:
attempt the theft of passwords. Non
Page 47 and 48:
IP networks are organized in terms
Page 49 and 50:
either the user or the trusted soft
Page 51 and 52:
However, the previous paragraph beg
Page 53 and 54:
Table 1. Internet Engineering Task
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
• Lightweight directory access pr
Page 61 and 62: mechanism to overcome the key distr
Page 63 and 64: Deployments that need to support mu
Page 65 and 66: Today’s Reality: Islands of Commu
Page 67 and 68: Simultaneously, IP addresses are al
Page 69 and 70: in-depth manner. Defense-in-depth m
Page 71 and 72: Protection Detection Reaction / Neu
Page 73 and 74: encrypted and then encapsulated wit
Page 75 and 76: Internet (grouping of autonomous sy
Page 77 and 78: via that same IP address. Specifica
Page 79 and 80: deployments. Regional flights that
Page 81 and 82: neighbor as a next hop after “Hol
Page 83 and 84: Interface Interface Customer Site S
Page 85 and 86: Interface Customer’s Application
Page 87 and 88: Although the vast majority of PBN s
Page 89 and 90: 6. RELATING SAFETY AND SECURITY FOR
Page 91 and 92: 6.1.1 Integrity. As section 4.3 ind
Page 93 and 94: As mentioned in section 4.4, the hi
Page 95 and 96: 6.1.4 Confidentiality. Confidential
Page 97 and 98: their own classification level nor
Page 99 and 100: integrity is not permitted to obser
Page 101 and 102: software has been confirmed as leve
Page 103 and 104: • Both safety and security are co
Page 105 and 106: Device at Safety level X Device at
Page 107 and 108: in a Biba Integrity Model environme
Page 109 and 110: Common Criteria Classes ACM—Confi
Page 111: (see section 9.10). A secure mechan
Page 115 and 116: concept, which is needed to create
Page 117 and 118: 4. Learn from past mistakes. Poor d
Page 119 and 120: exemplar airborne network architect
Page 121 and 122: • Requirement 8: Biba Integrity M
Page 123 and 124: Figure 31 shows how the recommended
Page 125 and 126: to-live (TTL) field in the IP heade
Page 127 and 128: using the traditional dual router i
Page 129 and 130: mechanism relies upon the controlle
Page 131 and 132: HAGs are high-assurance devices tha
Page 133 and 134: 8.3.5 Firewall. The firewall needs
Page 135 and 136: (AJ) or low probability of intercep
Page 137 and 138: design decisions that need to be de
Page 139 and 140: 9.2 INTEGRATED MODULAR AVIONICS IMP
Page 141 and 142: 9.3 USING PUBLIC IPs. The model and
Page 143 and 144: alerted the pilots because the fail
Page 145 and 146: environments. If the certification
Page 147 and 148: DSS (FIPS 186 [81]). Code signing i
Page 149 and 150: elationship with other equipment in
Page 151 and 152: approach is to keep the log informa
Page 153 and 154: 11. SUMMARY. Current civilian aircr
Page 155 and 156: environments should be extended to
Page 157 and 158: 12. COTS computer systems cannot be
Page 159 and 160: 14. NAS and airborne network archit
Page 161 and 162: 22. If SWAP considerations permit,
Page 163 and 164:
11.2 TOPICS NEEDING FURTHER STUDY.
Page 165 and 166:
9. Lee, Y., Rachlin, E., and Scandu
Page 167 and 168:
32. Loscocco, P., Smalley, S., Muck
Page 169 and 170:
59. Raisinghani, V. and Sridhar, I.
Page 171 and 172:
the following is a pointer to a rel
Page 173 and 174:
Department of Defense Instruction N
Page 175 and 176:
Information Assurance—The Departm
Page 177 and 178:
Threat source—Either (1) intent a
Page 179 and 180:
information found within these data
Page 181 and 182:
(HTTP) traffic (port 80), port scan
Page 183 and 184:
The simple network management proto
Page 185 and 186:
opportunities to crack the hosting
Page 187 and 188:
authorized to perform. 13 However,
Page 189 and 190:
sniffers, log-cleaning scripts, and
Page 191 and 192:
A.3.1 DENIAL OF SERVICE ATTACKS. Th
Page 193 and 194:
• Disclosure: Disclosure of routi
Page 195 and 196:
affected by the signal intermittenc
Page 197 and 198:
A-15. Barbir, A., Murphy, S., and Y
Page 199 and 200:
Survey Question What is the primary
Page 201 and 202:
Survey Question What is the primary
Page 203 and 204:
should be emphasized that there is
show all

Local Area Networks (LANs) in Aircraft - FTP Directory Listing - FAA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?