CVE-2020-1045 Microsoft ASP.NET Core Security Feature Bypass Vulnerability
High 7.5
Published
Updated
Check this codebase for CVE-2020-1045 and fix it if it is affected.
What it is: CVE-2020-1045 is a high-severity vulnerability in Fedoraproject Fedora, published on 11 Sep 2020. 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-2020-1045 in the wild and no public exploit code.
Affected packages and fixed versions:
- Microsoft.AspNetCore.App (NuGet): affected all versions; fixed in 2.1.22
- Microsoft.AspNetCore.App (NuGet): affected all versions; fixed in 2.1.22
- aspnet-core (Bitnami): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-arm (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-arm64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-musl-x64 (NuGet): affected from 3.1.0; fixed in 3.1.8
- Microsoft.AspNetCore.App.Runtime.linux-x64 (NuGet): affected from 3.1.0; fixed in 3.1.8
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-2020-1045/ (Markdown: https://insights.sbomify.com/CVE-2020-1045/index.md)
Attackers can bypass cookie security features by exploiting improper parsing of encoded cookie names in ASP.NET Core.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-1045?
CVE-2020-1045 is a high-severity vulnerability in Fedoraproject Fedora, published on 11 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
<p>A security feature bypass vulnerability exists in the way Microsoft ASP.NET Core parses encoded cookie names.</p> <p>The ASP.NET Core cookie parser decodes entire cookie strings which could allow a malicious attacker to set a second cookie with the name being percent encoded.</p> <p>The security update addresses the vulnerability by fixing the way the ASP.NET Core cookie parser handles encoded names.</p>
Which versions are affected by CVE-2020-1045?
27 open source packages ship an affected version, including Microsoft.AspNetCore.App, aspnet-core and Microsoft.AspNetCore.App.Runtime.linux-arm. It affects 6 products.
| Package | Affected | Fixed in |
|---|---|---|
Microsoft.AspNetCore.App NuGet | All versions | 2.1.22 |
Microsoft.AspNetCore.App NuGet | All versions | 2.1.22 |
aspnet-core Bitnami | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-arm NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-arm NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGet | From 3.1.0 | 3.1.8 |
21 more packages
Microsoft.AspNetCore.App.Runtime.linux-arm64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-musl-arm64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-musl-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.linux-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.osx-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.osx-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-arm NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-arm NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-arm64 NuGet | From 3.1.5 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-arm64 NuGet | From 3.1.5 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-x64 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-x86 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.App.Runtime.win-x86 NuGet | From 3.1.0 | 3.1.8 |
Microsoft.AspNetCore.Http NuGet | All versions | 2.1.22 |
Microsoft.AspNetCore.Http NuGet | All versions | 2.1.22 |
Microsoft.Owin NuGet | All versions | 4.1.1 |
Microsoft.Owin NuGet | All versions | 4.1.1 |
Linux distribution packages (13)
aspnetcore-runtime-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
aspnetcore-targeting-pack-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.108-2.el8_2 |
dotnet-apphost-pack-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-apphost-pack-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-host Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-host-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-hostfxr-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-hostfxr-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-runtime-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-runtime-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.8-2.el8_2 |
dotnet-sdk-3.1 Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.108-2.el8_2 |
dotnet-sdk-3.1-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.1.108-2.el8_2 |
Products include Fedoraproject Fedora, Microsoft Asp.net Core, Redhat Enterprise Linux, Redhat Enterprise Linux Aus, Redhat Enterprise Linux Eus, Redhat Enterprise Linux Tus.
How do I fix CVE-2020-1045?
Upgrade Microsoft.AspNetCore.App to 2.1.22 or later.
Is CVE-2020-1045 being exploited?
There is no known exploitation of CVE-2020-1045 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as BIT-aspnet-core-2020-1045, ECHO-cb59-aca0-0cd8, GHSA-hxrm-9w7p-39cc, RHSA-2020:3697, RHSA-2020:3699.