The old is new, again. CVE20112461 is back! presented at Troopers 2015

by Luca Carettoni, Mauro Gentile,

Summary : As a part of an ongoing investigation on Adobe Flash SOP bypass techniques, we identified a vulnerability affecting old releases of the Adobe Flex SDK compiler. Further investigation traced the issue back to a well known vulnerability (CVE20112461), already patched by Adobe. Old vulnerability, let's move on? Not this time. CVE20112461 is a very interesting bug. As long as the SWF file was compiled with a vulnerable Flex SDK, attackers can still use this vulnerability against the latest web browsers and Flash plugin. Even with the most recent updates, vulnerable Flex applications hosted on your domain can be exploited. In this presentation, we will disclose the details of this vulnerability (Adobe has never released all technicalities) and we will discuss how we conducted a large scale analysis on popular websites, resulting in the identification of numerous Alexa Top 50 sites vulnerable to this bug. Finally, we will also release a custom tool and a Burp plugin capable of detecting vulnerable SWF applications. If you’re a breaker, you will learn a new technique and enjoy our exploits. If you’re a builder, you will learn how to mitigate this attack. In both cases, you can help us to eradicate CVE20112461. After all, Troopers is about making the world a safer place.