8.1
High
Microsoft.AspNetCore.Identity

CVE-2023-33170

CVE-2023-33170 is a high-severity race condition vulnerability in Microsoft.AspNetCore.Identity (nuget), affecting versions < 2.1.39. It is fixed in 2.1.39, 2.2.4, 6.0.20, 7.0.9.

Key facts
CVSS score
8.1
High
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
Microsoft.AspNetCore.Identity
Fixed in
2.1.39, 2.2.4, 6.0.20, 7.0.9
Disclosed
2023

Summary

Microsoft Security Advisory CVE-2023-33170: .NET Security Feature Bypass Vulnerability Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in ASP.NET Core 2.1 and above. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A vulnerability exist in ASP.NET Core applications where account lockout maximum failed attempts may not be immediately updated, allowing an attacker to try more passwords. Discussion Discussion for this issue can be found at https://github.com/dotnet/aspnetcore/issues/49334 Mitigation factors Microsoft has not identified any mitigating factors for this vulnerability. Affected software Any ASP.NET 7.0 application running on .NET 7.0.8 or earlier. Any ASP.NET 6.0 application running on .NET 6.0.19 or earlier. Any ASP.NET Core 2.1 application consuming the package Microsoft.AspNetCore.Identity version 2.1.31 or earlier. If your application uses the following package versions, ensure you update to the latest version of .NET. ASP.NET Core 2.1 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.Identity | <=2.1.39 | 2.1.39 Microsoft.AspNet.Identity.Owin Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNet.Identity.Owin | <= 2.2.3 | 2.2.4 ASP.NET 6.0 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.linux-arm64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.linux-x64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.osx-arm64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.osx-x64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.win-arm | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.win-arm64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.win-x64 | <= 6.0.19 | 6.0.20 Microsoft.AspNetCore.App.Runtime.win-x86 | <= 6.0.19 | 6.0.20 ASP.NET 7.0 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- Microsoft.AspNetCore.App.Runtime.linux-arm | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.linux-arm64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.linux-musl-x64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.linux-x64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.osx-arm64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.osx-x64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.win-arm | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.win-arm64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.win-x64 | <= 7.0.9 | 7.0.9 Microsoft.AspNetCore.App.Runtime.win-x86 | <= 7.0.9 | 7.0.9 Advisory FAQ How do I know if I am affected? If you have a runtime or SDK with a version listed, or an affected package listed in affected software, you're exposed to the vulnerability. How do I fix the issue? To fix the issue please install the latest version of .NET 6.0 or .NET 7.0. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET SDKs. If you are using one of the affected packages, please update to the patched version listed above. If you have .NET 6.0 or greater installed, you can list the versions you have installed by running the dotnet --info command. You will see output like the following; If you're using .NET 7.0, you should download and install Runtime 7.0.7 or SDK 7.0.106 (for Visual Studio 2022 v17.4) from https://dotnet.microsoft.com/download/dotnet-core/7.0. If you're using .NET 6.0, you should download and install Runtime 6.0.18 or SDK 6.0.312 (for Visual Studio 2022 v17.2) from https://dotnet.microsoft.com/download/dotnet-core/6.0. If you're using ASP.NET Core 2.1 and consuming the Microsoft.AspNetCore.Identity package, update that package to version 2.1.39 .NET 6.0 and and .NET 7.0 updates are also available from Microsoft Update. To access this either type "Check for updates" in your Windows search, or open Settings, choose Update & Security and then click Check for Updates. Once you have installed the updated runtime or SDK, restart your apps for the update to take effect. Additionally, if you've deployed self-contained applications targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed. Other Information Reporting Security Issues If you have found a potential security issue in .NET 6.0 or .NET 7.0, please email details to [email protected]. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at <https://aka.ms/corebounty>. Support You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime and https://github.com/dotnet/aspnet/. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue. Disclaimer The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. External Links CVE-2023-33170 Revisions V1.0 (July 11, 2023): Advisory published. Version 1.0 Last Updated 2023-07-11

Impact

What is race condition?

Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.

Severity and exposure

CVE-2023-33170 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (2.1.39, 2.2.4, 6.0.20, 7.0.9). Upgrading removes the vulnerable code path.

Affected versions

nuget

  • Microsoft.AspNetCore.Identity (< 2.1.39)
  • Microsoft.AspNet.Identity.Owin (< 2.2.4)
  • Microsoft.AspNetCore.App.Runtime.linux-arm (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-arm (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-x64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-x86 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-x86 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.win-x64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.win-arm (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-arm (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (>= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (< 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (< 6.0.20)

Security releases

  • Microsoft.AspNetCore.Identity → 2.1.39 (nuget)
  • Microsoft.AspNet.Identity.Owin → 2.2.4 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-arm → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-x64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.osx-x64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-arm → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-arm64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-x64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-x86 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-x86 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-x64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-arm64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.win-arm → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.osx-x64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-x64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-arm → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 → 7.0.9 (nuget)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 → 6.0.20 (nuget)
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 → 6.0.20 (nuget)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2023-33170 is reachable in your applications. Explore open-source security for your team.

See if CVE-2023-33170 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade Microsoft.AspNetCore.Identity to 2.1.39 or later
  • Upgrade Microsoft.AspNet.Identity.Owin to 2.2.4 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 6.0.20 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2023-33170

What is CVE-2023-33170?

CVE-2023-33170 is a high-severity race condition vulnerability in Microsoft.AspNetCore.Identity (nuget), affecting versions < 2.1.39. It is fixed in 2.1.39, 2.2.4, 6.0.20, 7.0.9. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.

How severe is CVE-2023-33170?

CVE-2023-33170 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2023-33170?
  • Microsoft.AspNetCore.Identity (nuget) (versions < 2.1.39)
  • Microsoft.AspNet.Identity.Owin (nuget) (versions < 2.2.4)
  • Microsoft.AspNetCore.App.Runtime.linux-arm (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-arm64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.linux-x64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.osx-x64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-arm (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-arm64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-x64 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.win-x86 (nuget) (versions < 6.0.20)
  • Microsoft.AspNetCore.App.Runtime.osx-arm64 (nuget) (versions >= 7.0.0, < 7.0.9)
  • Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (nuget) (versions >= 7.0.0, < 7.0.9)
Is there a fix for CVE-2023-33170?

Yes. CVE-2023-33170 is fixed in 2.1.39, 2.2.4, 6.0.20, 7.0.9. Upgrade to this version or later.

Is CVE-2023-33170 exploitable, and should I be worried?

Whether CVE-2023-33170 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2023-33170 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2023-33170?
  • Upgrade Microsoft.AspNetCore.Identity to 2.1.39 or later
  • Upgrade Microsoft.AspNet.Identity.Owin to 2.2.4 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x86 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.win-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 7.0.9 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.linux-musl-x64 to 6.0.20 or later
  • Upgrade Microsoft.AspNetCore.App.Runtime.osx-arm64 to 6.0.20 or later

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