Quick take - A recent cybersecurity assessment has identified a critical server-side request forgery (SSRF) vulnerability in the Skipper Proxy, affecting Flask and Blazor web applications, which could allow unauthorized access to internal resources.

Fast Facts

A critical server-side request forgery (SSRF) vulnerability (CVE-2022-38580) was discovered in the Skipper Proxy, affecting Flask and Blazor web applications.
The vulnerability allows attackers to manipulate server requests, potentially exposing internal resources to unauthorized access.
The assessment utilized Burp Suite for reconnaissance, revealing open TCP ports and sensitive information through directory brute force attacks.
Organizations using Skipper Proxy are advised to review their security measures and patch vulnerabilities to mitigate risks associated with SSRF attacks.
Continuous security assessments and timely updates to web infrastructure are essential to protect against evolving cyber threats.

Critical Vulnerability Found in Skipper Proxy: A Threat to Flask and Blazor Sites

In a recent cybersecurity assessment, a significant vulnerability has been discovered within the Skipper Proxy, affecting web infrastructures that utilize Flask and Blazor applications. This vulnerability, identified as a server-side request forgery (SSRF), poses a substantial risk by potentially exposing internal resources to unauthorized access. The flaw has been documented under CVE-2022-38580.

Discovery and Analysis

The investigation began with the deployment of two web applications: a Flask site on TCP port 80 and a Blazor site on TCP port 3000. Both sites were managed by the Skipper Proxy. Using Burp Suite, cybersecurity experts conducted an initial reconnaissance phase, which revealed open TCP ports 22 (SSH), 80 (HTTP), and 3000 (HTTP). This scan provided crucial insights into the technologies in use.

Further analysis involved a directory brute force attack on the Flask site, uncovering a vacancies page and a job application form. These findings indicated potential exposure of sensitive information. Concurrently, the Blazor site was found to host a login form and was confirmed to be running on the Kestrel web server, commonly used for ASP.NET applications.

The most alarming discovery was the SSRF vulnerability within the Skipper Proxy. This flaw allows attackers to manipulate server requests, potentially accessing internal resources that should remain protected from external threats.

Implications for Organizations

The SSRF vulnerability in Skipper Proxy presents serious security risks for organizations relying on this proxy for routing internal requests. If exploited, it could lead to unauthorized data access and compromise sensitive internal systems. Organizations with similar configurations are strongly advised to review their security measures, patch identified vulnerabilities, and implement robust defenses against SSRF attacks.

Recommended Actions

To mitigate these risks, organizations should prioritize continuous security assessments and timely updates to their web infrastructure. Here are some essential steps:

Understand Your Tech Stack: Familiarize yourself with technologies like Flask, Skipper Proxy, and Blazor to better navigate vulnerabilities.
Leverage SSRF Vulnerabilities: Recognize how SSRF can be exploited to access otherwise unreachable internal services.
Conduct Thorough Reconnaissance: Use tools like nmap to identify open ports and services, providing insights into potential attack vectors.
Brute Force Subdomains: Perform brute force attacks on subdomains to uncover hidden endpoints that may exhibit vulnerabilities.

By following these guidelines, organizations can enhance their understanding of potential vulnerabilities and improve their ability to identify and address weaknesses effectively. As cyber threats continue to evolve, staying informed and proactive in cybersecurity practices remains crucial for safeguarding digital assets.

References