HEARTBLEED: Technical Description and Fixes - Syed Shamsudheen

HEARTBEAT

HeartBeat Extension to TLS - keep-alive – Similar to Ping Alternate for costly process (continuous data transfer) to determine whether the peer is alive or not. For every Request message send by client, Server has to answer that is send reply to client immediately. Implemented on 2012 by RFC 6520 [11]

HeartBeat HeartbeatRequest message and HeartbeatResponse message. HeartbeatRequest message from client can arrive almost at any time during the lifetime of a connection. Not more than one HeartbeatRequest message in flight at a time. No response within a particular amount time – TimeOut! – TLS ->Terminate Connection – DTLS -> Retransmit HeartbeatRequest message. [1]. Acunetix (2017, March 22). TLS/SSL Explained – Examples of a TLS Vulnerability and Attack, Final Part. Retrieved May 09, 2017, from https://www.acunetix.com/blog/articles/tls-vulnerabilities-attacks-final-part/ src: [1]

HEARTBLEED

HeartBleed Found by Neel Mehta, Google computer security employee, on 21, March 2014   ‘HeartBleed’ = ‘Heart’ (vulnerability in HeartBeat protocol) + ‘Bleed’ (data leakage). Happens due to improper input validation of HeartbeatRequest message.

HeartBleed [2]. Heartbleed. (2017, April 14). In Wikipedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Heartbleed&oldid=775427692 src: [2] Not everytime sensitive information will be received as the location of the data on the server side stored will be random.

TECHNICAL DETAIL

OPENSSL OpenSSL is an open source written in C language which is used for SSL/TLS protocols with HeartBeat extension. It was initiated on 1998, as of 2014, two third of the sites were using OpenSSL.

HeartBeatMessage in OPENSSL src: [3] [3]. Durumeric, Z., Kasten, J., Adrian, D., Halderman, J. A., Bailey, M., Li, F., Paxson, V. (2014). The Matter of Heartbleed. In Proceedings of the 2014 Conference on Internet Measurement Conference (pp. 475–488). New York, NY, USA: ACM. https://doi.org/10.1145/2663716.2663755 [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/ src: [4]

Processing HeartBeatRequest Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

Processing HeartBeatRequest Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

Processing HeartBeatRequest Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

Processing HeartBeatRequest Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

HeartBeatResponse Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

HeartBeatResponse Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

HeartBeatResponse Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

HeartBeatResponse Message src: [4] [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

In Memory Buffer UnderFlow src: [5] [5]. A technical view of theOpenSSL ‘Heartbleed’ vulnerability. (n.d.). Retrieved May 8, 2017, from https://www.ibm.com/developerworks/community/files/basic/anonymous/api/library/38218957-7195-4fe9-812a-10b7869e4a87/document/ab12b05b-9f07-4146-8514-18e22bd5408c/media src: [5]

IMPACT

Impact Clients sensitive information - passwords, private communication messages, financial details, anything that is worth protecting. Servers sensitive information - session ID, different tokens, Secret keys.  Mail servers, firewalls, VPN, Android, TOR, operating systems (like Debian Wheezy, Ubuntu 12.04.4 LTS and more) that shipped potential vulnerable OpenSSL [3]. [3]. Durumeric, Z., Kasten, J., Adrian, D., Halderman, J. A., Bailey, M., Li, F., Paxson, V. (2014). The Matter of Heartbleed. In Proceedings of the 2014 Conference on Internet Measurement Conference (pp. 475–488). New York, NY, USA: ACM. https://doi.org/10.1145/2663716.2663755

HeartBleed on YAHOO! src: [6] [6]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/ src: [6]

HeartBleed on Websites! [7]. Rubenking, B. N. J., April 10, 2014, & Comments, 14. (n.d.). Heartbleed: How It Works. Retrieved May 9, 2017, from http://www.pcmag.com/article2/0,2817,2456359,00.asp [8]. Heartbleed Report (2017-01). (n.d.). Retrieved May 08, 2017, from https://www.shodan.io/report/DCPO7BkV [9]. Rainie, L., & Duggan, M. (2014, April 30). Heartbleed’s Impact. Retrieved May 9, 2017, from http://www.pewinternet.org/2014/04/30/heartbleeds-impact/ [12]. Total number of Websites. (n.d.). Retrieved May 12, 2017, from http://www.internetlivestats.com/total-number-of-websites/ src: [7] Shodan on 2017 shows that nearly 200,000 websites (0.0002% [12] of the sites available online) are still vulnerable to HeartBleed [8] Because of these information leakage, as per Pew Research Center, “39% of internet users have changed passwords or canceled accounts; 6% think their personal information was swiped” [9].

SOLUTION

SOLUTION OpenSSL 1.0.1g fixed the Heartbleed bug on 7, April 2014 [10] and enabled it by default. SSL3 structure (s3->rrec) will have the correct record length. If anyone of the below condition is true, as per RFC 6520 sec. 4 [11], the server has to discard the message silently. [5]. A technical view of theOpenSSL ‘Heartbleed’ vulnerability. (n.d.). Retrieved May 8, 2017, from https://www.ibm.com/developerworks/community/files/basic/anonymous/api/library/38218957-7195-4fe9-812a-10b7869e4a87/document/ab12b05b-9f07-4146-8514-18e22bd5408c/media [10]. Durumeric, Z., Kasten, J., Adrian, D., Halderman, J. A., Bailey, M., Li, F., Paxson, V. (2014). The Matter of Heartbleed. In Proceedings of the 2014 Conference on Internet Measurement Conference (pp. 475–488). New York, NY, USA: ACM. https://doi.org/10.1145/2663716.2663755 [11]. Tuexen, M., Seggelmann, R., & Williams, M. (n.d.). Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension. Retrieved May 9, 2017, from https://tools.ietf.org/html/rfc6520 src: [5]

CONCLUSION

CONCLUSION HeartBleed without any doubt is one of the biggest stain on today’s fast moving internet. The bug went undetected for more than 2 years. Now the question is did anyone else notice it and just not tell the world? And has been using it quietly extracting information ever since? Well, this is a hard question for which we don’t have answer currently. Only time will tell how much damage it caused in the past.

REFERENCES [1]. Acunetix (2017, March 22). TLS/SSL Explained – Examples of a TLS Vulnerability and Attack, Final Part. Retrieved May 09, 2017, from https://www.acunetix.com/blog/articles/tls- vulnerabilities-attacks-final-part/ [2]. Heartbleed. (2017, April 14). In Wikipedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Heartbleed&oldid=775427692 [3]. Durumeric, Z., Kasten, J., Adrian, D., Halderman, J. A., Bailey, M., Li, F., Paxson, V. (2014). The Matter of Heartbleed. In Proceedings of the 2014 Conference on Internet Measurement Conference (pp. 475–488). New York, NY, USA: ACM. https://doi.org/10.1145/2663716.2663755 [4]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/ [5]. A technical view of theOpenSSL ‘Heartbleed’ vulnerability. (n.d.). Retrieved May 8, 2017, from https://www.ibm.com/developerworks/community/files/basic/anonymous/api/library/38218957 -7195-4fe9-812a-10b7869e4a87/document/ab12b05b-9f07-4146-8514-18e22bd5408c/media [6]. Anatomy of OpenSSL’s Heartbleed: Just four bytes trigger horror bug. Retrieved May 9, 2017, from https://www.theregister.co.uk/2014/04/09/heartbleed_explained/

REFERENCES [7]. Rubenking, B. N. J., April 10, 2014, & Comments, 14. (n.d.). Heartbleed: How It Works. Retrieved May 9, 2017, from http://www.pcmag.com/article2/0,2817,2456359,00.asp [8]. Heartbleed Report (2017-01). (n.d.). Retrieved May 08, 2017, from https://www.shodan.io/report/DCPO7BkV [9]. Rainie, L., & Duggan, M. (2014, April 30). Heartbleed’s Impact. Retrieved May 9, 2017, from http://www.pewinternet.org/2014/04/30/heartbleeds-impact/ [10]. Durumeric, Z., Kasten, J., Adrian, D., Halderman, J. A., Bailey, M., Li, F., Paxson, V. (2014). The Matter of Heartbleed. In Proceedings of the 2014 Conference on Internet Measurement Conference (pp. 475–488). New York, NY, USA: ACM. https://doi.org/10.1145/2663716.2663755 [11]. Tuexen, M., Seggelmann, R., & Williams, M. (n.d.). Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Heartbeat Extension. Retrieved May 9, 2017, from https://tools.ietf.org/html/rfc6520 [12]. Total number of Websites. (n.d.). Retrieved May 12, 2017, from http://www.internetlivestats.com/total-number-of-websites/

QUESTIONS!