Blogger API Content-Security-Policy Bypass Scanner

The Blogger API is widely used by developers and bloggers to manage their content across Google's blogging platform, Blogger. It enables programmatic content management, allowing users to create, edit, and delete posts programmatically. The API is essential for automating tasks and integrating with other applications for efficient blog management. It's extensively used by third-party applications to interact with Blogger's features and data. Being part of the Google ecosystem, it serves millions of users, making it a significant target for both developers and potential attackers. Ensuring its secure usage is crucial since the API handles various content management tasks online.

The vulnerability detected involves a potential Content-Security-Policy (CSP) bypass within the Blogger API. CSP is a crucial security feature that helps mitigate cross-site scripting (XSS) attacks by restricting resources the browser is allowed to load. This specific bypass can allow an attacker to inject scripts despite CSP restrictions, potentially leading to XSS attacks. Attackers may exploit this by embedding malicious scripts within the content managed by Blogger API. Successful exploitation could enable attackers to execute arbitrary JavaScript in the context of the user's browser session. It's an important vulnerability that demands attention to ensure the security of web applications utilizing Blogger API.

The vulnerability primarily targets the CSP headers that are meant to protect against XSS. Technical exploitation involves embedding a specially-crafted script into a Blogger feed URL, asserting control over CSP bypass through the API endpoints. A payload is injected to test the vulnerability by replacing parts of the query parameter in the API calls. The injection aims to trigger an alert, which stands as an indication of vulnerability presence. The CSP headers are checked for specific conditions that show their inadequacy, allowing unwanted content loading. It's a sophisticated exploit method that leverages API endpoints to circumvent standard security protocols.

If successfully exploited, this vulnerability can lead to severe consequences such as data theft through session hijacking and unauthorized actions in the context of the affected user. Attackers might execute malicious JavaScript, leading to exposure of sensitive information and potential manipulation of blog content. It can also degrade user trust in the application by allowing unauthorized actions. In severe scenarios, it could lead to complete account takeover or defacement of blog content managed through the API. Therefore, it's critical to address such vulnerabilities promptly to maintain the integrity and trustworthiness of the application.

REFERENCES

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