Youku ACS Content-Security-Policy Bypass Scanner

Youku ACS is an integral component used widely in digital streaming ecosystems, often leveraged by platforms to manage content security and access control. Developed by the Youku team, its primary function is to assure safe content streaming and prevent unauthorized access. It is prevalent in environments that rely heavily on media distribution, including large-scale streaming platforms. As a product, Youku ACS ensures that content access policies are enforced effectively, becoming a strategic tool for maintaining digital rights in a media-rich internet environment. By implementing robust security policies, it plays a crucial role in fortifying against unauthorized data exploitation.

Cross-Site Scripting (XSS) is a prevalent vulnerability that occurs when attackers inject malicious scripts into vulnerable applications. This specific scanner focuses on identifying instances where the Content-Security-Policy in Youku ACS may be bypassed, exposing it to XSS attacks. An insecure Content-Security-Policy configuration can lead to severe security breaches, allowing attackers to execute scripts in users' browsers. The vulnerabilities checked relate to how well the policy prevents unauthorized script execution. This scanner delineates environments susceptible to XSS, aiding in proactive policy adjustments to safeguard user data.

This vulnerability hinges on the manipulation of specific endpoints within the Youku ACS environment. The component particularly at risk is the configuration and enforcement of Content-Security-Policy headers. Through technical analysis, it becomes evident that improper policy enforcement allows adversaries to load scripts from unauthorized sources, leveraging this to gain unauthorized access or manipulate data. The flaw is detectable through payloads designed to reveal lax CSP implementations. These syntax checks ensure comprehensive policy adherence and oversight, critical for maintaining script execution security.

Exploiting a Content-Security-Policy bypass can have dire consequences. If attackers successfully inject scripts, they could potentially redirect users to illicit sites, capture sensitive information like cookies or authentication tokens, or perform unauthorized actions on behalf of users. The exploitation may lead to dissemination of malware or unauthorized data manipulation, compromising both user trust and data integrity. It underscores the critical need for robust and correctly configured security policies that deter such exploits while preserving system functionality.

REFERENCES

• https://github.com/renniepak/CSPBypass/blob/main/data.tsv