Biblio

Today, web browsers are a major avenue for cyber-compromise and data breaches. Web browser hardening, through high-granularity and least privilege tailored configurations, can help prevent or mitigate many of these attack avenues. For example, on a classic client desktop infrastructure, an enforced configuration that enables users to use one browser to connect to critical and trusted websites and a different browser for un-trusted sites, with the former restricted to trusted sites and the latter with JavaScript and Plugins disabled by default, may help prevent most JavaScript and Plugin-based attacks to critical enterprise sites. However, most organizations, today, still allow web browsers to run with their default configurations and allow users to use the same browser to connect to trusted and un-trusted sites alike. In this article, we present detailed steps for remotely hardening multiple web browsers in a Windows-based enterprise, for Internet Explorer and Google Chrome. We hope that system administrators use this guide to jump-start an enterprise-wide strategy for implementing high-granularity and least privilege browser hardening. This will help secure enterprise systems at the front-end in addition to the network perimeter.

The continuous discovery of exploitable vulnerabilitiesin popular applications (e.g., web browsers and documentviewers), along with their heightening protections against control flow hijacking, has opened the door to an oftenneglected attack strategy-namely, data-only attacks. In thispaper, we demonstrate the practicality of the threat posedby data-only attacks that harness the power of memorydisclosure vulnerabilities. To do so, we introduce memorycartography, a technique that simplifies the construction ofdata-only attacks in a reliable manner. Specifically, we showhow an adversary can use a provided memory mapping primitive to navigate through process memory at runtime, andsafely reach security-critical data that can then be modifiedat will. We demonstrate this capability by using our cross-platform memory cartography framework implementation toconstruct data-only exploits against Internet Explorer and Chrome. The outcome of these exploits ranges from simple HTTP cookie leakage, to the alteration of the same originpolicy for targeted domains, which enables the cross-originexecution of arbitrary script code. The ease with which we can undermine the security ofmodern browsers stems from the fact that although isolationpolicies (such as the same origin policy) are enforced atthe script level, these policies are not well reflected in theunderlying sandbox process models used for compartmentalization. This gap exists because the complex demands oftoday's web functionality make the goal of enforcing thesame origin policy through process isolation a difficult oneto realize in practice, especially when backward compatibility is a priority (e.g., for support of cross-origin IFRAMEs). While fixing the underlying problems likely requires a majorrefactoring of the security architecture of modern browsers(in the long term), we explore several defenses, includingglobal variable randomization, that can limit the power ofthe attacks presented herein.