BSides Detroit 12 Interviews 17

This week Josh Little is back as a host. Wolfgang and Josh talk to Prutha Parikh from Qualys, doing a technical talk. Last year Prutha found CVE-2011-4317, Apache Reverse Proxy Rewrite.

Abstract. This talk will discuss the Apache Reverse Proxy vulnerability (CVE-2011-4317) that I discovered while developing vulnerability signatures for Apache. Depending on the reverse proxy configuration, the vulnerability allows access to internal systems from the Internet.The presentation will start with discussion on reverse and forward proxies and look at some older reverse proxy vulnerabilities and patches. It will go into the thought process behind bypassing the latest patch to discover a new vulnerability to remotely gain access to the internal network. It will also describe the tools, techniques and ideas that went behind discovering the new variant of the vulnerability and constructing a proof of concept to exploit the issue. Along with exploring the root cause of the issue, it also talks about the issue from an attacker’s perspective and finally recommends protection mechanisms against the attack. The talk will also give the audience a peek into the process of vulnerability signature creation and discovering new vulnerabilities.I exercised responsible disclosure of the vulnerability to Apache and after the patch was released, I went public with my findings in a blog post. I will also share a standalone tool that will help system administrators identify the vulnerability in their environment.

This episode is cross-posted at Rats and Rogues.