Vimeo Content-Security-Policy Bypass Scanner

Vimeo is widely used by individuals and businesses for hosting, sharing, and streaming videos in high definition. The platform is popular among content creators due to its customization options and lack of advertisements. It serves a diverse group ranging from artists and filmmakers to businesses seeking to distribute their video content online. This extensive usage across various sectors makes it a crucial target for ensuring secure web practices. Security vulnerabilities in such a widespread platform could have far-reaching effects, impacting thousands of users worldwide. Therefore, regular audits and scans for vulnerabilities such as CSP bypasses are essential for maintaining its integrity.

A Content-Security-Policy (CSP) bypass can lead to Cross-Site Scripting (XSS) attacks, which allow attackers to inject malicious scripts into web pages viewed by other users. This vulnerability arises when a website's CSP is not configured correctly, enabling malicious content to bypass the policy's restrictions. Attackers can exploit this to execute unauthorized actions or steal sensitive information. XSS vulnerabilities are significant as they pose threats to user data confidentiality and can damage a website's reputation. Detecting and mitigating such vulnerabilities is crucial for protecting users and maintaining the trust of the Vimeo platform community.

The vulnerability details involve checking for CSP headers and attempting to bypass them using headless browser scripts. The detection process includes navigating to the target URL and executing specific payloads designed to trigger XSS via a CSP bypass. This includes utilizing certain JSON endpoints from Vimeo that can be manipulated to deliver scripts as a vector for attack. The use of headless browsers is particularly effective in this case, enabling simulation of real-world browser behavior which might expose more subtle implementations of CSP vulnerabilities. The endpoint focuses on whether injected scripts are executed successfully when CSP restrictions are in place, which would indicate a bypass.

Exploitations of a CSP bypass can have serious consequences, such as unauthorized access to user sessions, data exfiltration, and the distribution of malware. Successful exploitation can allow attackers to inject scripts that perform unwanted actions unbeknownst to users, including redirecting to phishing sites or altering page content. This compromises not only individual privacy but can lead to broader security incidents affecting many users. Additionally, the presence of such vulnerabilities can significantly tarnish the reputation of Vimeo as a secure service provider, potentially leading to loss of users and revenue.

REFERENCES

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