Bug 1906267 (CVE-2020-27836)

Summary:	CVE-2020-27836 cluster-ingress-operator: changes to loadBalancerSourceRanges overwritten by operator
Product:	[Other] Security Response	Reporter:	Jason Shepherd <jshepherd>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	aos-bugs, aos-network-edge-staff, bmontgom, eparis, jburrell, jokerman, nstielau, sponnaga
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	ose-cluster-ingress-operator-container-v4.6.0-202012161211.p0	Doc Type:	---
Doc Text:	A flaw was found in cluster-ingress-operator. A change to how the router-default service allows only certain IP source ranges could allow an attacker to access resources that would otherwise be restricted to specified IP ranges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-12-21 13:31:04 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:	1905490, 1906560
Bug Blocks:	1905803, 1939568

Description Jason Shepherd 2020-12-10 05:06:31 UTC

Until the 4.6.6 version of OpenShift Container Platform changes to the router-default service to allow only certain IP source ranges was possible by directly editing the service object [1]. Since 4.6.6 changes to the loadBalancerSourceRanges field are overwritten to the default of all IP ranges. If a cluster is affected by this issue an attacker can use the flaw to access resources which should be restricted to the specified IP ranges.

[1] https://access.redhat.com/solutions/5158751

Comment 4 Jason Shepherd 2020-12-10 05:12:24 UTC

Upstream commit:

https://github.com/openshift/cluster-ingress-operator/pull/507

Comment 5 Jason Shepherd 2020-12-14 22:59:35 UTC

Mitigation:

Move the allowed IP source ranges from the loadBalancerSourceRanges setting to "service.beta.kubernetes.io/load-balancer-source-ranges" annotation. For example: 

oc -n openshift-ingress annotate svc/router-default service.beta.kubernetes.io/load-balancer-source-ranges=10.0.0.0/8,192.168.0.0/16

Comment 6 errata-xmlrpc 2020-12-21 13:23:52 UTC

This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 4.6

Via RHSA-2020:5614 https://access.redhat.com/errata/RHSA-2020:5614

Comment 7 Product Security DevOps Team 2020-12-21 13:31:04 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-2020-27836