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>
References (6)
Core 6
Core References
Mailing List, Third Party Advisory vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LN2FUVBSVPGK7AU3NMLO3YR6CGONQPB/
Mailing List, Third Party Advisory vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ASICXQXS4M7MTAF6SGQMCLCA63DLCUT3/
Third Party Advisory
https://access.redhat.com/errata/RHSA-2020:3699
Release Notes, Third Party Advisory
https://github.com/dotnet/core/blob/main/release-notes/3.1/3.1.8/3.1.8.md#changes-in-318
Patch, Vendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1045
Third Party Advisory
https://security.snyk.io/vuln/SNYK-RHEL8-DOTNET-1439600
Scores
CVSS v3
7.5
EPSS
0.2040
EPSS Percentile
95.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
Status
published
Products (26)
fedoraproject/fedora
32
fedoraproject/fedora
33
microsoft/asp.net_core
2.1 - 2.1.21
nuget/Microsoft.AspNetCore.App
0 - 2.1.22NuGet
nuget/Microsoft.AspNetCore.App.Runtime.linux-arm
3.1.0 - 3.1.8NuGet
nuget/Microsoft.AspNetCore.App.Runtime.linux-arm64
3.1.0 - 3.1.8NuGet
nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-arm64
3.1.0 - 3.1.8NuGet
nuget/Microsoft.AspNetCore.App.Runtime.linux-musl-x64
3.1.0 - 3.1.8NuGet
nuget/Microsoft.AspNetCore.App.Runtime.linux-x64
3.1.0 - 3.1.8NuGet
nuget/Microsoft.AspNetCore.App.Runtime.osx-x64
3.1.0 - 3.1.8NuGet
... and 16 more
Published
Sep 11, 2020
Tracked Since
Feb 18, 2026