Preventing Capability Leaks in Secure JavaScript Subsets

Date Added: Jan 2010
Format: PDF

Publishers wish to sandbox third-party advertisements to protect themselves from malicious advertisements. One promising approach used by ADsafe, Dojo Secure, and Jacaranda, sandboxes advertisements by statically verifying that their JavaScript conforms to a safe subset of the language. These systems blacklist known dangerous properties that would let advertisements escape the sandbox. Unfortunately, this approach does not prevent advertisements from accessing new methods added to the built-in prototype objects by the hosting page. In this paper, the authors show that one-third of the Alexa US Top 100 web sites would be exploitable by an ADsafe-verified advertisement.