CVE-2021-31957 ASP.NET Core Denial of Service Vulnerability
Medium 5.9
Published
Updated
Check this codebase for CVE-2021-31957 and fix it if it is affected.
What it is: CVE-2021-31957 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 8 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-31957 in the wild and no public exploit code.
Affected packages and fixed versions:
- dotnet (Bitnami): affected from 5.0.0; fixed in 5.0.7
- dotnet-sdk (Bitnami): affected from 5.0.0; fixed in 5.0.7
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2021-31957/ (Markdown: https://insights.sbomify.com/CVE-2021-31957/index.md)
An attacker can cause a denial of service in applications using the .NET Core framework by exploiting a resource exhaustion flaw.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-31957?
CVE-2021-31957 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 8 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
ASP.NET Core Denial of Service Vulnerability
Weakness: CWE-400
Which versions are affected by CVE-2021-31957?
2 open source packages ship an affected version, including dotnet and dotnet-sdk. It affects 4 products.
| Package | Affected | Fixed in |
|---|---|---|
dotnet Bitnami | From 5.0.0 | 5.0.7 |
dotnet-sdk Bitnami | From 5.0.0 | 5.0.7 |
Linux distribution packages (38)
aspnetcore-runtime-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
aspnetcore-runtime-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
aspnetcore-targeting-pack-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
aspnetcore-targeting-pack-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet-apphost-pack-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-apphost-pack-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-apphost-pack-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-apphost-pack-5.0-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-host Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-host-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-hostfxr-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-hostfxr-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-hostfxr-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-hostfxr-5.0-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-runtime-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-runtime-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-runtime-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-runtime-5.0-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-sdk-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet-sdk-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet-sdk-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet-sdk-5.0-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet-targeting-pack-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.16-1.el8_4 |
dotnet-targeting-pack-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.7-1.el8_4 |
dotnet-templates-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet-templates-5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet3.1-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.116-1.el8_4 |
dotnet5.0 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet5.0-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
dotnet5.0-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
netstandard-targeting-pack-2.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:5.0.204-1.el8_4 |
rh-dotnet31-aspnetcore-runtime-3.1 Red Hat:rhel_dotnet:3.1::el7 | All versions | 0:3.1.16-1.el7_9 |
rh-dotnet31-aspnetcore-targeting-pack-3.1 Red Hat:rhel_dotnet:3.1::el7 | All versions | 0:3.1.16-1.el7_9 |
rh-dotnet31-dotnet Red Hat:rhel_dotnet:3.1::el7 | All versions | 0:3.1.116-1.el7_9 |
rh-dotnet31-dotnet-apphost-pack-3.1 Red Hat:rhel_dotnet:3.1::el7 | All versions | 0:3.1.16-1.el7_9 |
Products include Fedoraproject Fedora, Microsoft .Net, Microsoft .Net Core, Microsoft Visual Studio 2019.
How do I fix CVE-2021-31957?
Upgrade dotnet to 5.0.7 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-31957 being exploited?
There is no known exploitation of CVE-2021-31957 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as BIT-dotnet-2021-31957, BIT-dotnet-sdk-2021-31957, RHSA-2021:2350, RHSA-2021:2351, RHSA-2021:2352, RHSA-2021:2353.