Google APIs Blogger Content-Security-Policy Bypass Scanner

Google APIs Blogger is widely used by individuals and organizations to create and manage blogs. The service allows users to host and publish blogs with its own domain or subdomain, often integrating with other Google services. By utilizing Blogger API, developers can programmatically manage blog posts, comments, and users, providing a flexible platform for content dissemination. The platform's ease of use and comprehensive features make it a popular choice for both personal and commercial blogging activities. Additionally, Blogger provides templates and customization options to tailor the appearance of blogs according to personalized or brand-specific designs. As with many web-based platforms, ensuring its security is critical to prevent malicious exploitation.

The vulnerability detected in this context is a type of Content-Security-Policy (CSP) Bypass, which can lead to a Cross-Site Scripting (XSS) attack on Google APIs Blogger. CSP is a security feature that helps prevent a variety of attacks, including XSS, by restricting resources the browser can load for a given page. When a CSP bypass is possible, malicious scripts can execute in the context of users’ browsers. This vulnerability may allow attackers to perform unauthorized actions such as stealing session cookies or redirecting users to harmful sites. As CSP is a critical part of web security, a bypass indicates a significant flaw that can undermine the protection mechanisms in place for web applications.

Technical details of this vulnerability include the ability to inject scripts via Content-Security-Policy weaknesses on pages using Google APIs Blogger. The vulnerable endpoint is accessed when CSP rules fail to adequately filter or block harmful scripts. Attackers exploit this flaw by crafting a payload that navigates through the platform's CSP and injects malicious JavaScript content, potentially sourced from external domains like googleapis.com. Such scripts can bypass CSP checks due to misconfigurations or incomplete CSP policies, leaving applications vulnerable to exploitation.

The possible effects of this vulnerability, if exploited, include unauthorized access and data theft. Users could be tricked into executing harmful actions without their consent. Attackers may leverage the vulnerability to inject scripts that capture sensitive information such as login credentials. Additionally, exploitation of this CSP bypass can lead to defacement of webpages, disruption of services, and compromise of user trust. In severe cases, attackers could gain control over the web application, leading to further security breaches.

REFERENCES

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