Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.
How could an attacker exploit the vulnerability? An authenticated attacker could exploit the vulnerability by sending a malicious http request to the web server. According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of confidentiality (C:H), and integrity (I:H), and some loss of availability (A:L). What does that mean for this vulnerability? An attacker who successfully exploited this vulnerability could view sensitive information such as other user's credentials (Confidentiality) and make changes to file contents on the target server (Integrity), and they might be able to force a crash within the server (Availability). What should I do to make sure my ASP.NET Core application is protected? If you are running .NET 8 or later install the .NET update from Microsoft Update, then restart your application or reboot the machine. If you are running .NET 2.3 you must update the package reference for Microsoft.AspNet.Server.Kestrel.Core to 2.3.6, then recompile your application and redeploy. If you are running a self-contained/single-file application, install the .NET update, recompile your application and redeploy. According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability? An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities. What kind of security feature could be bypassed by successfully exploiting this vulnerability? An attacker who successfully exploited this vulnerability could smuggle another HTTP request and bypass front-end security controls or hijack other users' credentials. This vulnerability is rated as an Important, Security Feature Bypass that is less likely to be exploited. Why is the CVSS score 9.9 out of 10? ASP.NET Core is
Maturity: Exploit
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