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Vulnerability details: VCID-meg5-59nq-fbgk
Vulnerability ID VCID-meg5-59nq-fbgk
Aliases CVE-2023-21538
GHSA-8f7f-vqg5-jrv9
Summary # Microsoft Security Advisory CVE-2023-21538: .NET Denial of Service Vulnerability ## <a name="executive-summary"></a>Executive summary Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 6.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists in .NET 6.0 where a malicious client could cause a stack overflow which may result in a denial of service attack when an attacker sends an invalid request to an exposed endpoint. ## Discussion Discussion for this issue can be found at https://github.com/dotnet/runtime/issues/80449 ### <a name="mitigation-factors"></a>Mitigation factors Microsoft has not identified any mitigating factors for this vulnerability. ## <a name="affected-software"></a>Affected software * Any .NET 6.0 application running on .NET 6.0.12 or earlier. If your application uses the following package versions, ensure you update to the latest version of .NET. ### <a name=".NET 6"></a>.NET 6 Package name | Affected version | Patched version ------------ | ---------------- | ------------------------- [Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)|>= 6.0.0, <= 6.0.12|6.0.13 [Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)|>= 6.0.0, <= 6.0.12|6.0.13 ## Advisory FAQ ### <a name="how-affected"></a>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](#affected-software), you're exposed to the vulnerability. ### <a name="how-fix"></a>How do I fix the issue? * To fix the issue please install the latest version of .NET 6.0. 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 have .NET Core 3.1 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 are using one of the affected packages, please update to the patched version listed above. ``` .NET Core SDK (reflecting any global.json): Version: 6.0.300 Commit: 8473146e7d Runtime Environment: OS Name: Windows OS Version: 10.0.18363 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\6.0.300\ Host (useful for support): Version: 6.0.5 Commit: 8473146e7d .NET Core SDKs installed: 6.0.300 [C:\Program Files\dotnet\sdk] .NET Core runtimes installed: Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download ``` * If you're using .NET 6.0, you should download and install Runtime 6.0.13 or SDK 6.0.113 (for Visual Studio 2022 v17.1) from https://dotnet.microsoft.com/download/dotnet-core/6.0. .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](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) 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 secure@microsoft.com. 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-2023-21538]( https://www.cve.org/CVERecord?id=CVE-2023-21538) ### Revisions V1.0 (January 10, 2023): Advisory published. _Version 1.0_ _Last Updated 2023-01-10_
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (5)
CWE-502 Deserialization of Untrusted Data
CWE-121 Stack-based Buffer Overflow
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3 7.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-21538.json
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
epss 0.0085 https://api.first.org/data/v1/epss?cve=CVE-2023-21538
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-8f7f-vqg5-jrv9
cvssv3.1 7.5 https://github.com/dotnet/runtime
generic_textual HIGH https://github.com/dotnet/runtime
cvssv3.1 7.5 https://github.com/dotnet/runtime/security/advisories/GHSA-8f7f-vqg5-jrv9
cvssv3.1_qr HIGH https://github.com/dotnet/runtime/security/advisories/GHSA-8f7f-vqg5-jrv9
generic_textual HIGH https://github.com/dotnet/runtime/security/advisories/GHSA-8f7f-vqg5-jrv9
cvssv3.1 7.5 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GV5QDWYJ4C26JB7RTI55Z4O76WSH4FMV
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GV5QDWYJ4C26JB7RTI55Z4O76WSH4FMV
cvssv3.1 7.5 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZI27LYW5C4Z4644WYIQWOXBZL7WIP2X6
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZI27LYW5C4Z4644WYIQWOXBZL7WIP2X6
cvssv3.1 7.5 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
cvssv3.1 7.5 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
generic_textual HIGH https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
ssvc Track https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
cvssv3.1 7.5 https://nvd.nist.gov/vuln/detail/CVE-2023-21538
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2023-21538
cvssv3.1 7.5 https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21538
generic_textual HIGH https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21538
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-21538.json
https://api.first.org/data/v1/epss?cve=CVE-2023-21538
https://github.com/dotnet/runtime
https://github.com/dotnet/runtime/security/advisories/GHSA-8f7f-vqg5-jrv9
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GV5QDWYJ4C26JB7RTI55Z4O76WSH4FMV
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GV5QDWYJ4C26JB7RTI55Z4O76WSH4FMV/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZI27LYW5C4Z4644WYIQWOXBZL7WIP2X6
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZI27LYW5C4Z4644WYIQWOXBZL7WIP2X6/
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
https://nvd.nist.gov/vuln/detail/CVE-2023-21538
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21538
2158342 https://bugzilla.redhat.com/show_bug.cgi?id=2158342
GHSA-8f7f-vqg5-jrv9 https://github.com/advisories/GHSA-8f7f-vqg5-jrv9
RHSA-2023:0077 https://access.redhat.com/errata/RHSA-2023:0077
RHSA-2023:0078 https://access.redhat.com/errata/RHSA-2023:0078
RHSA-2023:0079 https://access.redhat.com/errata/RHSA-2023:0079
USN-5798-1 https://usn.ubuntu.com/5798-1/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2023-21538.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/dotnet/runtime
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/dotnet/runtime/security/advisories/GHSA-8f7f-vqg5-jrv9
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GV5QDWYJ4C26JB7RTI55Z4O76WSH4FMV
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZI27LYW5C4Z4644WYIQWOXBZL7WIP2X6
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C Found at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:Y/T:P/P:M/B:A/M:M/D:T/2024-07-16T22:02:43Z/ Found at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21538
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2023-21538
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-21538
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.74828
EPSS Score 0.0085
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:57:52.430612+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/01/GHSA-8f7f-vqg5-jrv9/GHSA-8f7f-vqg5-jrv9.json 38.0.0