Yandex ST Content-Security-Policy Bypass Scanner

The Yandex ST is a widely utilized platform within web development for hosting libraries such as JQuery and Bootstrap. It is used by developers to enhance the functionality and design of web applications efficiently, reducing the necessity for self-hosting these libraries. The platform is predominantly leveraged within digital environments where robust client-side scripting is required for high-performance web applications. By simplifying the integration of complex libraries, Yandex ST facilitates streamlined web development processes. Organizations and independent developers frequently utilize platforms like Yandex ST to ensure consistency across web applications while minimizing server load. Due to its broad adoption, ensuring its security within digital assets is paramount to maintaining overall web application security.

The detected vulnerability involves a bypass of Content-Security-Policy (CSP) within Yandex ST, leading to potential Cross-Site Scripting (XSS) attacks. CSP is a critical security feature in web browsers that helps to minimize XSS risks by restricting the resources that can be loaded. However, a CSP bypass can allow an attacker to inject and execute malicious scripts, compromising the integrity and security of client-side applications. This vulnerability can be exploited by crafted payloads that manipulate the DOM or execute unauthorized scripts. By targeting these kind of security misconfigurations, attackers can take unauthorized actions on behalf of legitimate users. Therefore, identifying and mitigating CSP bypass vulnerabilities is essential for maintaining a secure and trusted digital platform.

The technical details of the detected vulnerability focus on exploiting the CSP by injecting scripts through the Yandex ST CDN. Using various techniques, attackers may introduce scripts into web pages to manipulate functionality or extract sensitive user information. The vulnerability detection utilizes payload injection in the query part of requests, attempting to insert scripts that can interact with page elements. The flaw specifically allows for scripts located on the Yandex ST domain to be incorrectly trusted and therefore executed by a client's browser. When the injected script executes, it registers as a successful CSP XSS bypass, as indicated by the notification of a successful attack. This advanced intrusion method highlights the imperative need for enhanced CSP configurations and assessments.

Exploiting the detected vulnerability could lead to severe consequences, such as the unauthorized execution of scripts within users’ browsers, potentially leading to data theft or session hijacking. Attackers could manipulate the application to perform unintended actions on behalf of users, resulting in access to sensitive personal or corporate information. The integrity and availability of the compromised web application could be affected, causing a loss of trust and reputation from users and stakeholders. Moreover, unauthorized scripts could introduce additional malware or initiate further attacks against connected systems. Thus, mitigating the potential impacts of these vulnerabilities is crucial to preserving the confidentiality, integrity, and availability of web applications and their data.

REFERENCES

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