It was discovered that ASP.NET did not properly decode certain cookie values. A remote attacker could exploit this to bypass the "Cookie Prefixes" security mechanism by sending specially crafted cookies to a vulnerable web application.
Statement: The "Cookie Prefixes" feature is not used by default in ASP.NET. Successful exploitation likely requires a secondary vulnerability, for example a cross-site scripting issue.
External References: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1045 https://github.com/dotnet/aspnetcore/issues/23578 https://github.com/dotnet/aspnetcore/pull/24264
This issue has been addressed in the following products: .NET Core on Red Hat Enterprise Linux Via RHSA-2020:3697 https://access.redhat.com/errata/RHSA-2020:3697
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:3699 https://access.redhat.com/errata/RHSA-2020:3699
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2020-1045