Securing Legacy Firefox Extensions with SENTINEL

Abstract

Abstract.A poorly designed web browser extension with a security vulnerability may expose the whole system to an attacker. Therefore, attacks directed at "benign-but-buggy" extensions, as well as extensions that have been written with malicious intents pose significant security threats to a system running such components. Recent studies have indeed shown that many Firefox extensions are over-privileged, making them attractive attack targets. Unfortunately, users currently do not have many options when it comes to protecting themselves from extensions that may potentially be malicious. Once installed and executed, the extension needs to be trusted. This paper introduces Sentinel, a policy enforcer for the Firefox browser that gives fine-grained control to the user over the actions of existing JavaScript Firefox extensions. The user is able to define policies (or use predefined ones) and block common attacks such as data exfiltration, remote code execution, saved password theft, and preference modification. Our evaluation of Sentinel shows that our prototype implementation can effectively prevent concrete, realworld Firefox extension attacks without a detrimental impact on users' browsing experience.

OPEXA: analyser assistant for detecting over‐privileged extensions

“…Another dynamic approach was proposed by Onarlioglu [28]. User can use pre-defined or his own security policies to prevent attacks such as remote code execution and password theft.…”

SENTINEL: Securing Legacy Firefox Extensions

“…This paper is an extended version of the authors' previous work titled Securing Legacy Firefox Extensions with Sentinel [7].…”

“…This paper is an extended version of the authors' previous work titled Securing Legacy Firefox Extensions with Sentinel [7]. While the scope of our previous work is limited to proposing a defense against XPCOM-based extension attacks, this paper describes and addresses two additional attack classes (i.e., malicious XUL element manipulations and JavaScript namespace collision exploits) for achieving more comprehensive Firefox extension security.…”

EmPoWeb: Empowering Web Applications with Browser Extensions

“…Due to their privileged position in browsers, it is well understood that extensions pose serious security and privacy threats to user data [7], [8], [9], [10], [11], [12], [13]. Therefore, in order to limit extensions capabilities, a mandatory permission system requires that extensions explicitly declare the set of APIs they effectively need to access.…”