This vulnerability was discovered by a security researcher, Aleksandar Nikolic, who works as a penetration tester for a company in Serbia. The name of the bug is “Server-Side Request Forgery (SSRF)”. This bug could allow an attacker to execute a code on your server and steal your data. This bug affects .NET Framework, ASP.NET, and ASP.NET Core, and .NET Core apps.

How to check if you are vulnerable?

The easiest way to check if your server is vulnerable or not is by visiting the following url: http://localhost or http://127.0.0.1/.
If you see a message like the screenshot below, it means that your server is vulnerable and you need to fix it as soon as possible.

What is Server Side Request Forgery (SSRF)?

SSRF is a vulnerability in web servers that can be exploited by an attacker to execute code on your server. The exploit takes advantage of the fact that when an app sends a request to a server, it is not authenticated by the server and therefore could allow the attacker to execute code on your server and steal data from your application.

What is Server Side Request Forgery?

Server-Side Request Forgery (SSRF) is a vulnerability that allows an attacker to execute malicious code on a server. Server-Side Request Forgery is one of the most commonly exploited vulnerabilities and is present on most applications. This vulnerability can be found in .NET Framework, ASP.NET, and ASP.NET Core apps and also in .NET Core apps.

It allows an attacker to execute a command on the server without any authentication required, which can lead to data being stolen from your server by the attacker.

What is Server-Side Request Forgery?

Server-side request forgery is a vulnerability that can occur when there are no authentication checks on an application server. This vulnerability has the potential to be exploited by an attacker, who could use it to access sensitive information and perform unauthorized actions. Keep in mind that you should always have authentication checks in place to prevent hackers from exploiting this vulnerability.

So what can you do to protect yourself?

There are some things that you can do to protect your server if you have been vulnerable to Server-Side Request Forgery:
First, ensure that your app is not using external connecters and services such as a database or web service. You should also only use trusted external services like those provided by Microsoft Azure. Secondly, ensure that your app uses SSL/TLS encryption when communicating with a third party service like a database or web service. Finally, if TLS encryption is not available, implement HTTPOnly cookie flag on all of your pages or limit their visibility period by setting the expiry time after 6 hours

Timeline

Published on: 03/09/2022 17:15:00 UTC
Last modified on: 05/12/2022 16:27:00 UTC

References