Analysis of Critical .NET Vulnerability CVE-2025-55315: HTTP Request Smuggling Explained
By
ingve
7mo ago· 25 min readenInsight
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Summary
This article provides an in-depth technical analysis of CVE-2025-55315, a critical .NET vulnerability with a CVSS score of 9.9. The author explains HTTP request smuggling vulnerabilities in general, details how this specific vulnerability works in .NET, discusses potential attack scenarios, outlines Microsoft's fix, and provides guidance on protection measures. The content is written from a developer's perspective, offering technical explanations rather than professional security advice.
Key quotes
· 5 pulledMicrosoft have given the vulnerability a CVSS score of 9.9, their highest ever.
I explain how request smuggling vulnerabilities work in general, how it works in this case, what attackers could use it for, how the vulnerability was fixed, what you can do to protect yourself.
WARNING: I am not a security professional, so do not take anything in this post as gospel or advice. I'm just a developer trying to make sense of things.
This blog is where I share my experiences as I journey into ASP.NET Core.
I admit, that's a very click-baity headline, but Microsoft have given the vulnerability a CVSS score of 9.9, their highest ever.
Hi, my name is Andrew, or ‘Sock’ to most people. This blog is where I share my experiences as I journey into ASP.NET Core.
