CVE-2020-0603 — Microsoft.AspNetCore.All
HIGHCVE-2020-0603 is a high-severity (CVSS 8.8) Out-of-bounds Write vulnerability in Microsoft.AspNetCore.All. EPSS puts its 30-day exploitation probability at 21.2% (98th percentile). A fix is available for Microsoft.AspNetCore.All — see the affected versions and patch details below.
Remote code execution in ASP.NET Core
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
Microsoft.AspNetCore.All.NETMicrosoft.AspNetCore.App.NETMicrosoft.AspNetCore.App.NETMicrosoft.AspNetCore.App.NETMicrosoft.AspNetCore.Http.Connections.NETMicrosoft.AspNetCore.App.Runtime.linux-arm.NETMicrosoft.AspNetCore.App.Runtime.linux-arm64.NETMicrosoft.AspNetCore.App.Runtime.linux-musl-arm64+6 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
A remote code execution vulnerability exists in ASP.NET Core software when the software fails to handle objects in memory.An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user, aka 'ASP.NET Core Remote Code Execution Vulnerability'.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.AspNetCore.All | ≥ 2.1.0&&< 2.1.15 | 2.1.15dotnet add package Microsoft.AspNetCore.All --version 2.1.15 |
| .NETNuGet | Microsoft.AspNetCore.App | ≥ 3.1.0&&< 3.1.1 | 3.1.1dotnet add package Microsoft.AspNetCore.App --version 3.1.1 |
| .NETNuGet | Microsoft.AspNetCore.App | ≥ 3.0.0&&< 3.0.1 | 3.0.1dotnet add package Microsoft.AspNetCore.App --version 3.0.1 |
| .NETNuGet | Microsoft.AspNetCore.App | ≥ 2.1.0&&< 2.1.15 | 2.1.15dotnet add package Microsoft.AspNetCore.App --version 2.1.15 |
| .NETNuGet | Microsoft.AspNetCore.Http.Connections | ≥ 1.0.0&&< 1.0.15 | 1.0.15dotnet add package Microsoft.AspNetCore.Http.Connections --version 1.0.15 |
| .NETNuGet | Microsoft.AspNetCore.App.Runtime.linux-arm | ≥ 3.1.0&&< 3.1.1 | 3.1.1dotnet add package Microsoft.AspNetCore.App.Runtime.linux-arm --version 3.1.1 |
Affected Products
asp.net coremicrosoftenterprise linuxredhatenterprise linux eusredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.AspNetCore.All, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.AspNetCore.All to 2.1.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-0603 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| .NET Core on Red Hat Enterprise Linux | rh-dotnet30-dotnet-0:3.0.102-3.el7 | RHSA-2020:0134 |
| Red Hat Enterprise Linux 8 | dotnet3.0-0:3.0.102-2.el8_1 | RHSA-2020:0130 |
Frequently Asked Questions
Is CVE-2020-0603 in your dependencies?
Find it across NuGet, including transitive dependencies.