Bug 1873451 (CVE-2020-1045)

Summary:	CVE-2020-1045 dotnet: ASP.NET cookie prefix spoofing vulnerability
Product:	[Other] Security Response	Reporter:	Stefan Cornelius <scorneli>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	andrew.slice, bodavis, dbhole, kanderso, omajid, rwagner
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in ASP.NET. Certain cookie values are not properly decoded allowing a remote attacker to bypass the "Cookie Prefixes" security mechanism. The highest threat from this vulnerability is to data integrity.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-09-08 19:17:44 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1873452, 1873453, 1873454
Bug Blocks:	1873276

Description Stefan Cornelius 2020-08-28 11:48:48 UTC

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.

Comment 1 Stefan Cornelius 2020-08-28 11:48:54 UTC

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.

Comment 7 Stefan Cornelius 2020-09-08 18:01:31 UTC

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

Comment 8 errata-xmlrpc 2020-09-08 18:23:55 UTC

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

Comment 9 errata-xmlrpc 2020-09-08 19:01:45 UTC

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

Comment 10 Product Security DevOps Team 2020-09-08 19:17:44 UTC

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