HubSpot Forms Content-Security-Policy Bypass via Scanner

HubSpot Forms are widely used by businesses and marketing teams to capture lead information and integrate it into their CRM system. The forms allow customization and can be seamlessly embedded into websites, making them an essential tool for user engagement and data collection. They are generally employed in landing pages, contact pages, and other interactive web elements to facilitate communication with potential clients. The ease of integration and rich feature set make HubSpot Forms a popular choice among marketers and web developers for enhancing user interaction. Despite their utility, these forms need to be configured correctly to prevent security vulnerabilities. Regular security assessments are important to ensure that any unauthorized data exposure risks are mitigated.

The vulnerability in question is a potential Content-Security-Policy (CSP) Bypass that can lead to Cross-Site Scripting (XSS). XSS is a type of security issue where an attacker can execute scripts in another user’s browser. CSPs are used to control which resources are allowed to load on a webpage, aiming to provide mitigation against XSS attacks. If not configured properly, CSPs can be bypassed, allowing attackers to inject malicious scripts via forms or other inputs. The vulnerability in HubSpot Forms may allow attackers to exploit this CSP Bypass, compromising the security of the web application. It is crucial for developers to ensure CSPs are robustly configured to prevent such security flaws.

This vulnerability arises from a misconfiguration in the CSP or an inadequately implemented CSP policy which doesn't take into account all potential scripting sources. Attackers may take advantage of this misconfiguration by crafting specially designed URLs or scripts embedded in forms to bypass security checks. When users interact with such compromised forms, the malicious scripts get executed, potentially leaking sensitive data. This scanner aims to identify the presence of such vulnerabilities by inserting crafted scripts and checking the response behavior of the web application. The vulnerable endpoints are typically those handling form submissions or queries.

The exploitation of this vulnerability can lead to unauthorized execution of scripts on users' browsers, potentially resulting in data theft, session hijacking, or defacement of the website. It can also be used for phishing attacks, misinformation, or embedding unwanted content in legitimate webpages. Businesses could suffer reputational damage and loss of customer trust as a result of such exploits. Therefore, addressing CSP weaknesses is critical to maintaining the confidentiality, integrity, and availability of web applications.

REFERENCES

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