Pieter Robyns
ABSTRACT
Many of today's enterprise-scale wireless networks are protected by the WPA2-Enterprise Protected Extensible Authentication Protocol (PEAP). In this paper it is demonstrated how an attacker can steal a user's credentials and gain unauthorized access to such networks, by utilizing a class of vulnerable devices as MSCHAPv2 challenge response oracles. More specifically this paper explains how on these devices, Lightweight EAP (LEAP) MSCHAPv1 credentials can be captured and converted to PEAP MSCHAPv2 credentials by using a rogue Access Point. This man-in-the-middle vulnerability was found to be present in all current versions of Apple's iOS and OS X operating systems, and may impact other devices as well. A proof-of-concept implementation is available that shows how Authentication Server certificate validation and certificate pinning mechanisms may be bypassed. Mitigation strategies for the attack and protective actions which can be undertaken by end-users are also described in this paper.
- N. Asokan, V. Niemi, and K. Nyberg. Man-in-the-middle in tunnelled authentication protocols. In Security Protocols, pages 28--41. Springer, 2005. Google Scholar
Digital Library
- K. Bauer, H. Gonzales, and D. McCoy. Mitigating evil twin attacks in 802.11. In Performance, Computing and Communications Conference, 2008. IPCCC 2008. IEEE International, pages 513--516, Dec 2008.Google Scholar
- A. Cassola, W. Robertson, E. Kirda, and G. Noubir. A Practical, Targeted, and Stealthy Attack Against WPA Enterprise Authentication. In Proceedings of NDSS, volume 2013, 2013.Google Scholar
- M. Ciampa. CWNA Guide to Wireless LANs. Cengage Learning, 2012.Google Scholar
- Cisco. Dictionary Attack on Cisco LEAP Vulnerability, 2003. http://www.cisco.com/en/US/tech/tk722/tk809/technologies_security_notice09186a00801aa80f.html.Google Scholar
- A. DeKok and A. Sulmicki. Cisco LEAP protocol description, 2001. http://freeradius.org/rfc/leap.txt.Google Scholar
- T. Dierks and E. Rescorla. The Transport Layer Security (TLS) Protocol. RFC 5246, IETF, August 2008.Google Scholar
- M. S. Gast. 802.11 Wireless Networks: The Definitive Guide, Second Edition. O'Reilly, 2005. Google ScholarDigital Library
- A. Gupta, R. Cozza, and C. Lu. Market Share analysis: Mobile phones, worldwide, 4Q13 and 2013. Gartner, 2014.Google Scholar
- S. Hartman and M. Wasserman. Extensible Authentication Protocol (EAP) Mutual Cryptographic Binding. RFC 7029, IETF, October 2013.Google Scholar
- C. He and J. C. Mitchell. Analysis of the 802.11 i 4-way handshake. In Proceedings of the 3rd ACM workshop on Wireless security, pages 43--50. ACM, 2004. Google ScholarDigital Library
- K. Hutchison. Wireless Intrusion Detection Systems. SANS Institute InfoSec Reading Room, October 2004.Google Scholar
- M. Marlinspike. Divide and Conquer: Cracking MS-CHAPv2, 2012. https://www.cloudcracker.com/blog/2012/07/29/cracking-ms-chap-v2/.Google Scholar
- Microsoft. Cryptobinding, 2014 (accessed). http://msdn.microsoft.com/en-us/library/cc238384.aspx.Google Scholar
- L. Nussel. The Evil Twin problem with WPA2-Enterprise. SUSE Linux Products GmbH, 2010.Google Scholar
- A. Palekar, D. Simon, J. Salowey, H. Zhou, G. Zorn, and S. Josefsson. Protected EAP Protocol (PEAP). Work in Progress 6, IETF, March 2003.Google Scholar
- A. Palekar, D. Simon, J. Salowey, H. Zhou, G. Zorn, and S. Josefsson. Protected EAP Protocol (PEAP) Version 2. Work in Progress 10, IETF, October 2004.Google Scholar
- V. Roth, W. Polak, E. Rieffel, and T. Turner. Simple and effective defense against evil twin access points. In Proceedings of the First ACM Conference on Wireless Network Security, WiSec '08, pages 220--235, New York, NY, USA, 2008. ACM. Google ScholarDigital Library
- B. Schneier, Mudge, and D. Wagner. Cryptanalysis of Microsoft's PPTP Authentication Extensions. CQRE '99, October 1999. Google ScholarDigital Library
- R. Siles. EAP dumb-down attack. In RootedCON 2013, pages 27--28. DinoSec, 2013.Google Scholar
- J. Wright. FreeRADIUS-WPE, 2008. http://www.willhackforsushi.com/?page_id=37.Google Scholar
- Z. Yang, A. C. Champion, B. Gu, X. Bai, and D. Xuan. Link-layer protection in 802.11i wlans with dummy authentication. In Proceedings of the Second ACM Conference on Wireless Network Security, WiSec '09, pages 131--138, New York, NY, USA, 2009. ACM. Google ScholarDigital Library
- J. Yavor. The BYOD PEAP Show. In DefCon 21. iSEC Partners, 2013.Google Scholar
- G. Zorn. Microsoft PPP CHAP Extensions, Version 2. RFC 2759, IETF, January 2000.Google Scholar
- G. Zorn and S. Cobb. Microsoft PPP CHAP Extensions. RFC 2443, IETF, October 1998.Google Scholar
Index Terms
- Short paper: exploiting WPA2-enterprise vendor implementation weaknesses through challenge response oracles
Recommendations
Short Communication: Cryptanalysis of a mutual authentication scheme based on nonce and smart cards
To prevent the forged login attacks, Liu et al. recently proposed a new mutual authentication scheme using smart cards. However, we demonstrate that the attacker without any secret information can successfully not only impersonate any user to cheat the ...
A Comparative Study of Authentication Methods for Wi-Fi Networks
CICSYN '11: Proceedings of the 2011 Third International Conference on Computational Intelligence, Communication Systems and NetworksIEEE 802.11X, which is a key part of IEEE 802.11i, employs extensible authentication protocol (EAP) to support a variety of upper layer authentication methods each with different benefits and drawbacks. Any one of these authentication methods can be the ...
ID-based threshold proxy signcryption scheme from bilinear pairings
A (t, n) threshold proxy signcryption scheme allows t or more proxy signcrypters from a designated group of n proxy signcrypters to signcrypt messages on behalf of an original signcrypter. In this paper, a new identity-based threshold proxy signcryption ...
Comments