In 2011, a significant privacy breach was uncovered involving Epic Marketplace, an online advertising network that served banners on major websites such as CNN and Orbitz. The company exploited a decade-old browser flaw to access users' browsing histories, enabling them to deliver highly targeted advertisements based on sensitive personal information, including indications of pregnancy.

Background of the Browser Flaw

The vulnerability in question was a well-documented issue in web browsers that allowed websites to determine which links a user had previously visited. This was achieved by analyzing the color changes of visited links, a feature intended to enhance user navigation. By rapidly querying thousands of links per second, malicious scripts could compile detailed profiles of users' interests and behaviors. Epic Marketplace utilized this technique to infer personal details, such as pregnancy status, by identifying visits to related websites. (theregister.com)

Implications and Impact

The exploitation of this browser flaw raised significant concerns about user privacy and the ethical boundaries of targeted advertising. By accessing sensitive information without consent, companies like Epic Marketplace violated user trust and potentially exposed individuals to unwanted solicitations or discrimination. The Federal Trade Commission (FTC) intervened, leading to a settlement that required Epic Marketplace to destroy the data collected through these practices and cease such activities in the future. (arstechnica.com)

Technical Details

The attack method involved embedding JavaScript code into websites that, when visited by users, would execute scripts to test numerous links per second. By detecting the color changes of visited links, the script could determine which specific URLs a user had accessed. This rapid querying allowed for the compilation of detailed user profiles, including sensitive information like pregnancy status, based on the assumption that users had visited related websites. (theregister.com)

Conclusion

The case of Epic Marketplace underscores the critical importance of robust privacy protections in the digital age. It highlights the need for continuous vigilance and proactive measures to safeguard user data against unauthorized access and exploitation. Users are encouraged to stay informed about potential privacy risks and to utilize tools and practices that enhance their online security.

References

This article provides a comprehensive overview of the exploitation of browser vulnerabilities in targeted advertising, emphasizing the importance of user privacy and the need for ethical data practices.