ARE WE SECURITY YET?Cristian Vat, @deathy

Geek.

Security Enthusiast

Problem: HTTP is not encrypted

• Traffic can be passively intercepted• Including your cookies/sessions, personal information

• Can be targeted for ads or more malicious reasons

• Traffic can be manipulated• Ad injection

• Malware injection

Content Injection

https://dannyman.toldme.com/2010/12/23/swa-yahoo-being-evil/

Solution: HTTPS

• Or is it SSL? Or TLS? Which version again?

• SSL 1.0 – not released, serious flaws

• SSL 2.0 – February 1995, multiple flaws

• SSL 3.0 – 1996

• great start…

• 1999 – TLS 1.0

• 2006 – TLS 1.1

• 2008 – TLS 1.2

• 2016-2017 – TLS 1.3, some early adopters already

HTTPS Vulnerabilities

• Renegociation attack

• DROWN

• CRIME

• BEAST

• POODLE

• RC4

• Heartbleed

• FREAK

• LOGJAM

Configuration complexityssl_protocols TLSv1 TLSv1.1 TLSv1.2;

ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-

SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-

RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-

SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-

SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-

SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-

SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-

SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-

SHA:DES-CBC3-SHA:!DSS';

ssl_prefer_server_ciphers on;

Solution: Configuration Generator

• https://mozilla.github.io/server-side-tls/ssl-config-generator/

Problem: HTTP links/requests

• Browsers still default to HTTP on port 80, which is OK

• Some clients may not support HTTPS

• Bookmarks

• It’s a web of links. Old links and you can’t update them all.

Solution: Redirect to HTTPS!

• HTTP Redirect: • Client: GET http://somesite.ro/

• Server: 301 Redirect to https://somesite.ro/

• JavaScript … $ curl -i http://www.homebank.ro/

HTTP/1.1 200 OK

content-length: 148

content-type: text/html

date: Fri, 17 Feb 2017 12:51:43 GMT

last-modified: Fri, 25 Oct 2013 22:58:06 GMT

p3p: CP="NON CUR OTPi OUR NOR UNI"

<script>

//redirect to public junction for login!

document.location="https://www.homebank.ro/public/HomeBankLogin/jsp/index.jsp";

</script>

Problem: Many slow redirects

• You’re still possibly redirecting every individual link

• Caching of redirects: • “It depends”

• Possible cause of bugs even if you just want to switch “http:” to “https:”

• No clear browser knowledge that page should only be used on HTTPS.

• Solution?

Solution: HSTS saves the day!

• HTTP Strict Transport Security• On valid HTTPS request the server sends a new HTTP Header:

• Browser will redirect all HTTP requests to HTTPS internally until expiry

• Even if user manually types an “http://” link!

Strict-Transport-Security: max-age=<expire-time>; includeSubDomains

Problem: First request fresh browser

• Fresh browser install

• Never visited a certain website before

• Nothing in HSTS cache

Solution: HSTS Preload

• Need a valid HSTS setup

• Go to https://hstspreload.org/ and submit your site to preload list

• Chrome preload list: https://chromium.googlesource.com/chromium/src/net/+/refs/heads/master/http/transport_security_state_static.json

• Gets baked in to Chrome, Firefox, Internet Explorer downloads/updates.

• Currently holds 80 “.ro” domains. (2 of them mine, banks seen: only brd.ro and unicredit.ro )

Problem: Security by Coincidence

• Just a very small sample. flanco.ro:

Our dev team who manages the our public website has mistakenly

configured the preload function + include_includesubdomains. This

feature has blocked our internal websites as well, even if the don’t > use

SSL at all. :(

hovie.at:

We cannot support HTTPS on the following subdomains:

• andrew.hovie.at - I don't have to time

to manage my own server anymore, so I switched to a hosting

provider, wildcard certs are expensive, they do not support certs

with multiple domains.

Also, when I enabled preload, I did not actually know what I am doing,

I was just following the recommendation from https://cipherli.st/.

chrishamper.com:

I had enabled the HSTS header with the "preload" directive on my domain

while

following an online guide related to HSTS, which didn't explain the

meaning or

repercussions of that directive. It is now causing much trouble when

attempting to do development work using subdomains I'm spinning up as

needed.

The CA Problem

• CA “Mafia”

• Making money from nothing

• HTTPS certificate cost may be prohibitive for personal websites

Solution: Let’s Encrypt

• Free domain validated certificates

• Fast, automatic

• Same security as anything else

• No wildcard/EV

• Short expiration date

The other CA problem

• Any CA can issue certs for any domain

• China CA can issue certificate for your US-based website

• Active attacks or bugs in CA validation

• See DigiNotar

Solution: HTTP Public Key Pinning

• Pin Public Keys of CAs which are allowed to issue certs for your site• Need at least 2 pins.

• You can break your site…

• Certificate Transparency

Problem: Library/Framework CSS/JS

• The Website is Slow

• Static Resource Serving is slow

• I don’t want to manage/package library JS/CSS

Solution: CDNs to the rescue!

• Load jQuery/Bootstrap/etc. from CDN

• Problem:• Now you depend on the CDN’s security

• Requests may be intercepted

• Active JS content running in your page may be modified by the CDN

Solution: Subresource Integrity

• Include the hash of a known good version in the <script> or <link> tag in your page

• Browser downloads resource but checks hash before applying styles/script to page.

<script src="https://example.com/example-framework.js" integrity="sha384-oqVuAfXRKap7fdgcCY5uykM6+R9GqQ8K/uxy9rx7HNQlGYl1kPzQho1wx4JwY8wC"crossorigin="anonymous"></script>

Resources

• https://www.ssllabs.com/ssltest/

• https://securityheaders.io/

• https://www.hardenize.com/

SO... ARE WE SECURITY YET?