The Bug that made me President: A Browser- and Web-Security Case Study on Helios Voting

Mario Heiderich, Tilman Frosch, Marcus Niemietz, Jörg Schwenk

International Conference on E-voting and Identity (VoteID), 2011, Tallinn, Estonia, September 2011


This paper briefly describes security challenges for critical web applications such as the Helios Voting system. After analyzing the Helios demonstration website we discovered several small flaws that can have a large security critical impact. An attacker is able to extract sensitive information, manipulate voting results, and modify the displayed information of Helios without any deep technical knowledge or laboratory-like prerequisites. Displaying and processing trusted information in an untrustworthy user agent can lead to the issue that most protection mechanisms are useless. In our approach of attacking Helios voting systems we do not rely on an already infected or trojanized machine of the user, instead we use simple and commonly known web browser features to leverage information disclosure and state modification attacks. We propose that online voting applications should at least follow the latest vulnerability mitigation guidelines. In addition, there should be thorough and frequent coverage with automated as well as manual penetrations tests in privacy sensitive applications. E-Voting software driven by web browsers are likely to become an attractive target for attackers. Successful exploitation can have impact ranging from large scale personal information leakage, financial damage, calamitously intended information and state modification as well as severe real life impact in many regards.


tags: e-voting