Post on 15-Dec-2015
transcript
USING PROXIES TO SECURE APPLICATIONS AND MOREBy Josh Sokol
# whoami
Josh Sokol (josh.sokol@ni.com) B.S. in Computer Science Cisco Certified Network Associate
(CCNA) SANS GIAC in Web Application
Security (GWAS) Web Systems Engineer for National
Instruments Own the Web Systems “Security
Practice”
Some Questions To Be Answered What’s this proxy thing everyone is
talking about? When and why should I use a proxy? My company doesn’t like to spend
money on security so why are you wasting my time?
Talk is cheap…show me how it works!
What is a Proxy?
A process that accepts requests for some service and passes them on to the real server.
Request
Request
Proxy
Types of Proxies
Caching Proxy Web Proxy Content-filtering Web Proxy Anonymizing Proxy Hostile Proxy Intercepting Proxy Forced Proxy Open Proxy Reverse Proxy
•Firefox
•Extension: SwitchProxy
•Tor and Privoxy
Act I – Anonymizing Proxies
Anonymizing Proxies
http://www.whatismyip.com Start Tor and Privoxy Select “Tor” from SwitchProxy http://www.whatismyip.com
Am I really anonymous?Kinda, but not really. My HTTP requests are being passed through the proxy, but what about DNS? Also, does my proxy know who I am? Yes!
Problems•Speed•False sense of security
Proxy 4 Free List
http://www.proxy4free.com/page1.html
•Apache
•mod_proxy
Act II – Reverse Proxies
Reverse Proxies
ProxyRequests Off<Location /owasp> ProxyPass http://www.owasp.org ProxyPassReverse
http://www.owasp.org Order allow,deny allow from all</Location>
http://doughboy.homeip.net/owasp
Benefits of Reverse Proxies Single machine acts as a gateway to
the real servers in the network. Use mod_cache (and
mod_mem_cache) to keep static documents in memory.
Single point of authentication
•Firefox
•Extension: SwitchProxy
•Extension: Tamper Data | Google Ratproxy | OWASP WebScarab
Act III – Intercepting Proxies
Tamper Data
Use tamperdata to view and modify HTTP/HTTPS headers and post parameters.
Trace and time http response/requests.
Security test web applications by modifying POST parameters.
Tamper Data Example
http://www.altoromutual.com Username: jsmith Password: Demo1234
Google Ratproxy
A semi-automated, largely passive web application security audit tool, optimized for an accurate and sensitive detection, and automatic annotation, of potential problems and security-relevant design patterns based on the observation of existing, user-initiated traffic in complex web 2.0 environments.
Detects and prioritizes broad classes of security problems, such as dynamic cross-site trust model considerations, script inclusion issues, content serving problems, insufficient XSRF and XSS defenses, and much more.
Using Ratproxy with Cygwin Install Cygwin with make, gcc-core,
openssl-dev, and openssl utilities. Download Ratproxy. Modify the make file by removing the “-
Wno-pointer-sign”. Download the Flare action script
decompiler. “make” Ratproxy. Add the Cygwin libraries to your
Windows path.
Google RatProxy Example
ratproxy.exe –v C:\cygwin –w ratproxy.log –p 8282 –d yourdomain.com –lfscm
Tell SwitchProxy to use Ratproxy. Surf! sh ratproxy-report.sh ratproxy.log >
report.html
OWASP WebScarab
WebScarab is a framework for analyzing applications that communicate using the HTTP and HTTPS protocols.
In its most common usage, WebScarab operates as an intercepting proxy, allowing the operator to review and modify requests created by the browser before they are sent to the server, and to review and modify responses returned from the server before they are received by the browser.
OWASP WebScarab Example
Start WebScarab. Check the “Proxy” tab to verify port
configuration. Tell SwitchProxy to use WebScarab. Surf http://www.altoromutual.com! Change cookie information. Change GET/POST information.
OWASP WebScarab Example 2
Web Services Google search for inurl:”?wsdl” http://
www.altoromutual.com/bank/ws.asmx?WSDL
http://www.weather.gov/forecasts/xml/SOAP_server/ndfdXMLserver.php?wsdl
http://terraservice.net/TerraService.asmx?WSDL
http://webservices.amazon.com/AWSECommerceService/AWSECommerceService.wsdl
Other Cool Features of WebScarab Site Spider XSS/CSRF Session ID Analysis Fuzzer
Other FREE Proxy Software
Paros (http://www.parosproxy.org/) Through Paros's proxy nature, all HTTP and HTTPS
data between server and client, including cookies and form fields, can be intercepted and modified.
Burp Suite (http://portswigger.net/suite/) Burp Suite is an integrated platform for attacking
web applications. It contains all of the Burp tools with numerous interfaces between them designed to facilitate and speed up the process of attacking an application. All tools share the same robust framework for handling HTTP requests, authentication, downstream proxies, logging, alerting and extensibility.