When the internet bleeded

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