CloudFront Content-Security-Policy Bypass Scanner

CloudFront is a content delivery network provided by Amazon Web Services that is widely used by companies to improve the speed and reliability of their web applications. It distributes content globally through a network of data centers, ensuring that data is delivered from locations nearest to end-users. Many organizations opt for CloudFront for its scalability and integration with other AWS services. Due to its frequent use, maintaining strong security measures is paramount. Proper security controls ensure that the data being delivered remains secure and unaltered. Vulnerabilities within CloudFront configurations can have wide-reaching implications.

The vulnerability related to CloudFront that this scanner detects is a Content Security Policy (CSP) Bypass leading to Cross-Site Scripting (XSS). CSP is a security standard designed to prevent XSS, clickjacking, and other code injection attacks. An attacker could exploit misconfigured CSP settings to execute malicious scripts. This form of bypass can result in unauthorized access to sensitive information, user account compromise, and the manipulation of data displayed on the client-side. Identifying and mitigating CSP bypass vulnerabilities is crucial to maintaining web application security. Ensuring proper CSP implementation helps defend against automated and targeted attacks alike.

The technical details involve inspecting the headers and payloads. The scanner works by navigating to the target URL and attempting to inject scripts through identified vectors. It looks for specific indicators in the HTTP headers and checks for opportunities to inject JavaScript. The matching criteria are based on detecting the presence of CSP headers that can be bypassed using cloudfront.net scripts. For fuzzing, payloads are injected into query parameters to observe their handling, leveraging AngularJS for script execution. By assessing the data flow and manipulation capabilities, the scanner discerns potential vulnerabilities that could be exploited.

Potential effects of exploiting this vulnerability include unauthorized data access, session hijacking, and defacement of web applications. Attackers can exploit the vulnerability to gain control over users' browsing sessions, steal cookies, and conduct phishing attacks. Manipulating the user interface or stealing sensitive user information could lead to significant reputational damage for the affected organization. Moreover, compromised applications can serve as a base for further network penetration or attacks, making mitigation efforts crucial. Understanding the full impact of a CSP bypass attack helps security teams prioritize remediation efforts effectively.

REFERENCES

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