🛡️ CVE-2020-1045 — aspnet-core

🟠 CVSS 8.0 — High ✅ No Known Exploit OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Cookie parsing failure

A security feature bypass vulnerability exists in the way Microsoft ASP.NET Core parses encoded cookie names.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.The security update addresses the vulnerability by fixing the way the ASP.NET Core cookie parser handles encoded names., aka 'Microsoft ASP.NET Core Security Feature Bypass Vulnerability'.

Affected software

CVE-2020-1045 is recorded against 14 packages.

  • aspnet-core
  • microsoft.aspnetcore.app (fixed in 2.1.22)
  • microsoft.aspnetcore.app.runtime.linux-arm (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.linux-arm64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.linux-musl-arm64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.linux-musl-x64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.linux-x64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.osx-x64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.win-arm (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.win-arm64 (from 3.1.5 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.win-x64 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.app.runtime.win-x86 (from 3.1.0 up to 3.1.8)
  • microsoft.aspnetcore.http (fixed in 2.1.22)
  • microsoft.owin (fixed in 4.1.1)

Timeline and source

Published on 6 March 2024 and last revised on 20 May 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

access.redhat.com (Web)
github.com (Web)
lists.fedoraproject.org (Web)
lists.fedoraproject.org (Web)
portal.msrc.microsoft.com (Web)
security.snyk.io (Web)
nvd.nist.gov (Web)

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2024-03-06
Updated 2026-08-12
Modified 2025-05-20
Fix URL N/A

Affected Packages

Software From version Fixed in
aspnet-core — —
microsoft.aspnetcore.app — 2.1.22
microsoft.aspnetcore.app.runtime.linux-arm 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.linux-arm64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.linux-musl-arm64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.linux-musl-x64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.linux-x64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.osx-x64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.win-arm 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.win-arm64 3.1.5 3.1.8
microsoft.aspnetcore.app.runtime.win-x64 3.1.0 3.1.8
microsoft.aspnetcore.app.runtime.win-x86 3.1.0 3.1.8
microsoft.aspnetcore.http — 2.1.22
microsoft.owin — 4.1.1

Similar Threats

Site Security Check

Is aspnet-core part of your stack?

CVE-2020-1045 is rated CVSS 8.0 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.