When the internet bleeded
A presentation at RootConf 2014 in in Bengaluru, Karnataka, India by Anant Shrivastava
When the Internet Bleeded Anant Shrivastava (@anantshri) for RootConf 2014
Topic of Discussion • Various SSL/TLS related issues in public – Heartbleed – GNUTLS Bug – Apple Bug – Lucky13 – BEAST – CRIME • What it means for Developers / Administrators. Ref : Pixabay.com
GIST of Security “Most of the Security protocols are broken“ • SSL == inSecure Socket Layer
1000 Feet view of TLS / SSL Bugs
HeartBleed (Openssl Bug) Ref : XKCD.com
HeartBleed (Openssl Bug) Ref : XKCD.com
GOTO FAIL : GNU TLS / Apple ● ● ● ● Functions which verifies x509 certificates. Invalid certificates can be passed off as genuine, even though they’re invalid. GNUTLS Details : http://blog.existentialize.com/the-story-of-the-gnutls-bug.html Apple : https://www.imperialviolet.org/2014/02/22/applebug.html Test yourself : https://gotofail.com/
BEAST’s LUCKY13 CRIME • BEAST (CBC Ciphers) – Allows retrial of encrypted data by key guess based on block based ciphers. • CRIME (compressed connection / SPDY) – Exploit compression to extract data ● LUCKY13 – cryptographic timing attack • RC4 – (http://blog.cryptographyengineering.com/2013/03/attack-ofweek-rc4-is-kind-of-broken-in.html)
Status Quo • SSL 3.0 / TLS 1.0 is broken at nearly all algorithm / protection level either reasonable exploits or conceptual exploitation available. • Catch 22 : If you protect against BEAST you are vulnerable to LUCKY13 and vice-versa
Lets Understand Heartbleed • Massive Effect over INTERNET but limited to OpenSSL • Effective Marketing and promotion • Known not just in Information Security Community but to the world • In short a lucky draw worth 64KB max of data (data =! information)
Twitter Reactions Ref : Twitter.com
Reactions Ref : Twitter.com
DIY • Server : heartbleed.anantshri.info Test Scripts : • http://heartbleed.anantshri.info/test.txt (Shell) • http://heartbleed.anantshri.info/hbtest.txt (Python) • Login Page : https://heartbleed.anantshri.info/login_post.html • https://heartbleed.anantshri.info/login.html • Video Demo
Trivia Facts • First well thought out exploit release where public presentation had prime focus (domain registered 2 days before announcement). • 3 different sources found same issue within a gap of a week. • Multiple exploits came out based on initial script which only looked at TLS 1.1 and not of 1.2 and 1.0 hence a lot of the servers were marked safe even when they were not • Hugely undervalued exploit even by author. Original founder didn’t expected the private key disclosure. • Akamai opensourced its solution for key safety and same was hacked left right center within few hours.
Trivia Facts • Not a protocol fault rather implementation flaw and hence GNUTLS, Mozilla NSS or Microsoft SSL is not effected. • 75 of Cisco Products found effected • Tor among effected products • OpenSSL 1.0.1 through 1.0.1f • LibreSSL (stripped down OpenBSD implementation) • OpenSSL Bugbounty • According to CloudFlare, GlobalSign’s CRL grew from 22KB before Heartbleed to 4.9MB afterward. • The number of revoked certificates on the CRL increased from 1,492 to 133,243. And that was just GlobalSign’s CRL
Reverse Heartbleed : Client Attack • Script – https://github.com/Lekensteyn/pacemaker
So What? ● ● Administrators – Patch meticulously – Monitor religiously – Co-relate, cross-ref, leverage bigdata identify anomoly and act on it. Developers – Not just a admin task – Start caring about older version of libraries. – Do not bundle dependencies or maintain updates – OpenSource MORE EYES != LESS SECURITY BUGS
Technical solutions • Enable TLS 1.1 and 1.2 • Enable forward secrecy • Change SSL certificate (I know there is a revocation cost) • Going forward you are secure till no one finds a flaw in newer algorithms
Perfect Forward Secrecy • random public keys per session for the purposes of key agreement with generation using non deterministic algorithm. • Even if connection is compromised it makes sure compromise affects only one connection.
Policy based solution • Fail hard, Fail early : Setup exigency process in place :Inform customers if you suspect foul play. Keep them updated. Block login if required. • Force password reset : Don’t inform and ask them to change : force it. • Don’t forget API Keys and other secrets • Keep hardware support subscriptions relevant or get lifetime support : it helps
Grave scenario Ref : http://www.edrawsoft.com/images/network/Cisco%20Network%20Diagram_Full.png
Questions? Ref : XKCD.com
Thanks for Listening Anant Shrivastava http://www.anantshri.info Freelance Consultant / Trainer RHCE, SANS GWAPT, CEH Web, Mobile and Linux
The talk will talk about various TLS / SSL related bugs that are identified in past year.
HeartBleed GNUTLS Bug Apple SSL Bug Lucky 13 BEAST CRIME These bugs have shaken the core premise of Secure communication. The talk will focus on bringing a basic understanding of these issues to the administrators or developers. Besides this the talk will also focus on some burning questions that are now raised in wild. Such as
- How secure are secure Socket Libraries?
- Is opensource code really secure?
- Is it really true that “given enough eyeballs, all bugs are shallow”?
- Should we move towards higher abstract languages?
And most important: What it really means for a Administrator / DevOps person
Video
Resources
The following resources were mentioned during the presentation or are useful additional information.
Buzz and feedback
Here’s what was said about this presentation on social media.
