ASP.NET Machine Keys Vulnerability Enables Remote Code Execution

2025-02-08

Learn about the risks of using insecure ASP.NET machine keys and how CloudGuard can help secure web server environments against such vulnerabilities.

Microsoft has identified a security risk where developers are using publicly disclosed ASP.NET machine keys, making web servers vulnerable to remote code execution. Threat actors exploit this by crafting malicious ViewState objects using these keys, which are then sent to targeted websites to gain control via code injection. The issue is widespread, with over 3,000 keys publicly accessible, facilitating easier exploitation.

Key Facts

Risks:

Web App/Website Vulnerability, Hardcoded Secrets, Shadow IT/Exposed Assets

Keywords:

ASP.NET, machine keys, remote code execution, ViewState, web server security, Microsoft warning

CVE:

N/A

Affected:

ASP.NET, Web servers

Article Body

Microsoft Warns of ASP.NET Key Vulnerability Leading to Remote Code Execution

Microsoft has issued a warning about a significant security risk involving ASP.NET machine keys. Developers have been unknowingly putting their web applications at risk by using publicly available ASP.NET machine keys from code documentation and repositories. This practice exposes web servers to potential remote code execution (RCE) attacks.

How the Attack Works

The attack exploits a feature known as ViewState, which is a method used by ASP.NET applications to maintain the state of a webpage between requests. If attackers obtain the machine keys, they can manipulate the ViewState to inject malicious code into a targeted website. This is achieved by sending a crafted POST request to the web server, which processes the malicious ViewState and compromises the system.

Widespread Vulnerability

Microsoft's research has uncovered over 3,000 machine keys that have been publicly disclosed, significantly lowering the barrier for cybercriminals to exploit this vulnerability. These keys are typically found in code documentation and open-source repositories, making them easily accessible to threat actors.

Potential Impact

The exploitation of these machine keys can lead to unauthorized access and control over web server environments. Organizations relying on ASP.NET for their web applications are particularly vulnerable and need to take immediate action to secure their environments.

Recommended Actions

To mitigate this risk, developers should ensure that they use unique and secure machine keys for each application. Regularly updating and auditing web application configurations can help prevent unauthorized access. Additionally, implementing robust security practices, such as monitoring and logging, can aid in detecting and responding to potential threats.

Read More

https://www.darkreading.com/remote-workforce/microsoft-public-asp-net-keys-web-server-rce