Nuxt.js Local File Inclusion Scanner

Nuxt.js is a popular framework built on top of Vue.js for developing modern web applications with server-side rendering, static sites, and single-page applications. It is used by web developers and companies to create performant, production-ready applications with simplicity. Often employed by enterprises needing fast, SEO-friendly web interfaces, the framework supports modular design, which extends its functionality through plugins and modules. Furthermore, Nuxt.js offers a convenient development experience with hot-reloading, and its community contributes extensively to its ecosystem, making it a preferred choice for dynamic, content-heavy applications. The product's wide adaptation is due to its extensive capabilities that cater to multiple deployment targets and development challenges. Its robustness is enhanced by its developer-friendly documentation and wide-ranging community support.

Local File Inclusion (LFI) is a type of vulnerability that allows attackers to include files on a server through the web browser. This occurs when an application dynamically includes files submitted via the browser without proper validation or sanitization. The vulnerability can exploit server misconfigurations and gain insight into sensitive files, eventually leading to further exploitation like credential harvesting or server compromise. Commonly, LFI is a consequence of insecure coding or negligent web application architecture that doesn't account for file path validation. Attackers can manipulate file path parameters in HTTP requests to traverse directories and access restricted files in the server's filesystem. This vulnerability is particularly significant in web applications where file handling processes are inadequately secured.

The vulnerability in Nuxt.js arises due to the improper configuration of Vite within the framework, which allows unauthorized file retrieval from the filesystem. The endpoints "/_nuxt/@fs/etc/passwd" and "/_nuxt/@fs/windows/win.ini" illustrate the specific points where the issue manifests by potentially exposing system files. A crucial aspect of this threat involves the regex matchers designed to identify vulnerable patterns, such as "root:.*:0:0:" in Unix files or sections within Windows initialization files. These patterns highlight the potential for LFI exploitation, rendering the system files accessible for unauthorized reading. With such configurations, attackers may traverse and retrieve sensitive system information that could be leveraged for escalated attacks or information disclosure.

The exploitation of this LFI vulnerability could lead to severe consequences, including unauthorized access to system files and subsequent elevation of privileges by the attacker. By gaining entry to sensitive files such as "/etc/passwd" or "win.ini," adversaries can extract information like usernames, hashed passwords, and system configurations. This intrudes on privacy and business-critical data integrity, potentially enabling further exploitation or denial of service if core files are accessed or tampered with. The risk amplifies in environments where security practices aren't rigorously enforced, making this a critical vulnerability for organizations that rely on Nuxt.js in their application stack. Successful exploitation could facilitate a broader range of attacks, from data leakage to compromise of the entire application infrastructure.

REFERENCES

• https://huntr.dev/bounties/4849af83-450c-435e-bc0b-71705f5be440/
• https://bryces.io/blog/nuxt3
• https://twitter.com/fofabot/status/1669339995780558849