CVE-2018-8171 Security feature bypass vulnerability exists in ASP.NET when the number of incorrect login attempts is not validated
Attackers can bypass account lockout mechanisms in ASP.NET applications by exploiting a lack of validation for incorrect login attempts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-8171?
CVE-2018-8171 is a high-severity vulnerability in Microsoft ASP.NET, published on 11 Jul 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A Security Feature Bypass vulnerability exists in ASP.NET when the number of incorrect login attempts is not validated, aka "ASP.NET Security Feature Bypass Vulnerability." This affects ASP.NET, ASP.NET Core 1.1, ASP.NET Core 1.0, ASP.NET Core 2.0, ASP.NET MVC 5.2.
Weakness: CWE-287
Which versions are affected by CVE-2018-8171?
8 open source packages ship an affected version, including Microsoft.AspNetCore.Identity. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.AspNetCore.Identity NuGet | From 1.0.0 | 1.0.6 |
Microsoft.AspNetCore.Identity NuGet | From 1.0.0 | 1.0.6 |
Microsoft.AspNetCore.Identity NuGet | From 1.1.0 | 1.1.6 |
Microsoft.AspNetCore.Identity NuGet | From 1.1.0 | 1.1.6 |
Microsoft.AspNetCore.Identity NuGet | From 2.0.0 | 2.0.4 |
Microsoft.AspNetCore.Identity NuGet | From 2.0.0 | 2.0.4 |
2 more packages
Microsoft.AspNetCore.Identity NuGet | From 2.1.0 | 2.1.2 |
Microsoft.AspNetCore.Identity NuGet | From 2.1.0 | 2.1.2 |
Products include Microsoft Asp.net Core, Microsoft Asp.net Model View Controller, Microsoft Asp.net Webpages.
How do I fix CVE-2018-8171?
Upgrade Microsoft.AspNetCore.Identity to a fixed version for your release line: 1.0.6, 1.1.6, 2.0.4 or 2.1.2.
Is CVE-2018-8171 being exploited?
There is no known exploitation of CVE-2018-8171 in the wild and no public exploit code.
Other vulnerabilities in Microsoft ASP.NET
- CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability
- CVE-2026-88092 ASP.NET Core Tampering Vulnerability
- CVE-2026-40372 ASP.NET Core Elevation of Privilege Vulnerability
- CVE-2021-43877 ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability
- CVE-2020-0603 Remote code execution in ASP.NET Core
Sources
Also known as GHSA-vhvh-528q-ff3p.