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Fencer Vulns
high 7.5

CVE-2023-21538 json

.NET Denial of Service Vulnerability

published 2023-01-10 3 y ago modified 2026-06-17 4 mo ago also BIT-dotnet-2023-21538 , BIT-dotnet-sdk-2023-21538 , BIT-powershell-2023-21538 , EUVD-2023-0406 , GHSA-8f7f-vqg5-jrv9

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

.NET Denial of Service Vulnerability

Patch / fix

  • nuget Microsoft.NETCore.App.Runtime.linux-arm 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.linux-arm64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.linux-musl-arm 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.linux-musl-arm64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.linux-musl-x64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.linux-x64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.osx-arm64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.osx-x64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.win-arm 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.win-arm64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.win-x64 6.0.13
  • nuget Microsoft.NETCore.App.Runtime.win-x86 6.0.13
  • bitnami dotnet 6.0.1
  • bitnami dotnet-sdk 6.0.1
  • Microsoft .NET 6.0 6.0.13
  • Microsoft PowerShell 7.2 7.2.9
  • dotnet6 Ubuntu 22.04 LTS 6.0.113-0ubuntu1~22.04.1

ubuntu advisories UBUNTU-CVE-2023-21538

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dotnet6.0 RHEL 9 6.0.113-1.el9_1
  • dotnet-sdk-6.0 RHEL 9 6.0.113-1.el9_1
  • dotnet-hostfxr-6.0 RHEL 9 6.0.13-1.el9_1
  • dotnet-runtime-6.0 RHEL 9 6.0.13-1.el9_1
  • dotnet-templates-6.0 RHEL 9 6.0.113-1.el9_1
  • aspnetcore-runtime-6.0 RHEL 9 6.0.13-1.el9_1
  • dotnet-apphost-pack-6.0 RHEL 9 6.0.13-1.el9_1
  • dotnet-targeting-pack-6.0 RHEL 9 6.0.13-1.el9_1

red hat advisories RHSA-2023:0077RHSA-2023:0078RHSA-2023:0079

  • dotnet-sdk-6.0 AlmaLinux 9 6.0.113-1.el9_1
  • dotnet-hostfxr-6.0 AlmaLinux 9 6.0.13-1.el9_1
  • dotnet-runtime-6.0 AlmaLinux 9 6.0.13-1.el9_1
  • dotnet-templates-6.0 AlmaLinux 9 6.0.113-1.el9_1
  • aspnetcore-runtime-6.0 AlmaLinux 9 6.0.13-1.el9_1
  • dotnet-apphost-pack-6.0 AlmaLinux 9 6.0.13-1.el9_1
  • dotnet-targeting-pack-6.0 AlmaLinux 9 6.0.13-1.el9_1
  • aspnetcore-targeting-pack-6.0 AlmaLinux 9 6.0.13-1.el9_1

almalinux advisories ALSA-2023:0077ALSA-2023:0079

  • dotnet6.0 Rocky Linux 8 6.0.113-1.el8_7
  • dotnet6.0 Rocky Linux 9 6.0.113-1.el9_1

rocky linux advisories RLSA-2023:0079RLSA-2023:0077

  • dotnet6-build Alpine 3.20, Alpine 3.19, Alpine 3.18 +2 more 6.0.113-r0
  • dotnet6-runtime Alpine 3.20, Alpine 3.19, Alpine 3.18 +2 more 6.0.13-r0

alpine advisories ALPINE-CVE-2023-21538

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-21538 updated cvss 7.5

dotnet: Parsing an empty HTTP response as a JSON.NET JObject causes a stack overflow and crashes a process

  • Red Hat .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet60-dotnet 6.0.113-1.el7_9, rh-dotnet60-dotnet-host 6.0.13-1.el7_9, rh-dotnet60-dotnet-sdk-6.0 6.0.113-1.el7_9, rh-dotnet60-dotnet-hostfxr-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-runtime-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-templates-6.0 6.0.113-1.el7_9, +6 more Red Hat .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet60-dotnet 6.0.113-1.el7_9, rh-dotnet60-dotnet-host 6.0.13-1.el7_9, rh-dotnet60-dotnet-sdk-6.0 6.0.113-1.el7_9, rh-dotnet60-dotnet-hostfxr-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-runtime-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-templates-6.0 6.0.113-1.el7_9, +6 more Red Hat .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet60-dotnet 6.0.113-1.el7_9, rh-dotnet60-dotnet-host 6.0.13-1.el7_9, rh-dotnet60-dotnet-sdk-6.0 6.0.113-1.el7_9, rh-dotnet60-dotnet-hostfxr-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-runtime-6.0 6.0.13-1.el7_9, rh-dotnet60-dotnet-templates-6.0 6.0.113-1.el7_9, +6 more
    fixed: vendor fix RHSA-2023:0078
  • Red Hat CodeReady Linux Builder (v. 8) dotnet-sdk-6.0-source-built-artifacts 6.0.113-1.el8_7
    fixed: vendor fix RHSA-2023:0079
  • Red Hat CodeReady Linux Builder (v. 9) dotnet-sdk-6.0-source-built-artifacts 6.0.113-1.el9_1
    fixed: vendor fix RHSA-2023:0077
  • Red Hat Enterprise Linux AppStream (v. 8) dotnet6.0 6.0.113-1.el8_7, dotnet-sdk-6.0 6.0.113-1.el8_7, dotnet-hostfxr-6.0 6.0.13-1.el8_7, dotnet-runtime-6.0 6.0.13-1.el8_7, dotnet-templates-6.0 6.0.113-1.el8_7, aspnetcore-runtime-6.0 6.0.13-1.el8_7, +3 more
    fixed: vendor fix RHSA-2023:0079
  • Red Hat Enterprise Linux AppStream (v. 9) dotnet6.0 6.0.113-1.el9_1, dotnet-sdk-6.0 6.0.113-1.el9_1, dotnet-hostfxr-6.0 6.0.13-1.el9_1, dotnet-runtime-6.0 6.0.13-1.el9_1, dotnet-templates-6.0 6.0.113-1.el9_1, aspnetcore-runtime-6.0 6.0.13-1.el9_1, +3 more
    fixed: vendor fix RHSA-2023:0077
  • Red Hat .NET Core 3.1 on Red Hat Enterprise Linux rh-dotnet31-dotnet, rh-dotnet31-dotnet-host, rh-dotnet31-dotnet-sdk-3.1, rh-dotnet31-dotnet-hostfxr-3.1, rh-dotnet31-dotnet-runtime-3.1, rh-dotnet31-dotnet-templates-3.1, +6 more Red Hat .NET Core 5.0 on Red Hat Enterprise Linux rh-dotnet50-dotnet, rh-dotnet50-dotnet-host, rh-dotnet50-dotnet-sdk-5.0, rh-dotnet50-dotnet-hostfxr-5.0, rh-dotnet50-dotnet-runtime-5.0, rh-dotnet50-dotnet-templates-5.0, +6 more Red Hat Enterprise Linux 8 dotnet, dotnet7.0, dotnet-host, dotnet-sdk-7.0, dotnet-hostfxr-7.0, dotnet-runtime-7.0, +7 more Red Hat Enterprise Linux 9 dotnet7.0, dotnet-host, dotnet-sdk-7.0, dotnet-hostfxr-7.0, dotnet-runtime-7.0, dotnet-templates-7.0, +6 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

2.84% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 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
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
nuget Microsoft.NETCore.App.Runtime.linux-arm
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.linux-arm64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.linux-musl-arm
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.linux-musl-arm64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.linux-musl-x64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.linux-x64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.osx-arm64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.osx-x64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.win-arm
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.win-arm64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.win-x64
>=6.0.0, <6.0.13
6.0.13
nuget Microsoft.NETCore.App.Runtime.win-x86
>=6.0.0, <6.0.13
6.0.13
bitnami dotnet
>=6.0.0, <6.0.1
6.0.1
bitnami dotnet-sdk
>=6.0.0, <6.0.1
6.0.1
bitnami powershell
>=7.2.0, <=7.2.0
 no fix listed

Affected products

  • Microsoft .NET 6.0
  • Microsoft PowerShell 7.2

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.