Bug 1848612 (CVE-2020-11767)

Summary:	CVE-2020-11767 istio/envoy: forward proxy between the victim and the origin leads to information disclosure
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	oarribas, rcernich
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Last Closed:	2021-10-28 02:04:42 UTC	Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1848614

Description Dhananjay Arunesh 2020-06-18 15:42:07 UTC

Istio through 1.5.1 and Envoy through 1.14.1 have a data-leak issue. If there is a TCP connection (negotiated with SNI over HTTPS) to *.example.com, a request for a domain concurrently configured explicitly (e.g., abc.example.com) is sent to the server(s) listening behind *.example.com. The outcome should instead be 421 Misdirected Request. Imagine a shared caching forward proxy re-using an HTTP/2 connection for a large subnet with many users. If a victim is interacting with abc.example.com, and a server (for abc.example.com) recycles the TCP connection to the forward proxy, the victim's browser may suddenly start sending sensitive data to a *.example.com server. This occurs because the forward proxy between the victim and the origin server reuses connections (which obeys the specification), but neither Istio nor Envoy corrects this by sending a 421 error. Similarly, this behavior voids the security model browsers have put in place between domains.

References:
https://bugs.chromium.org/p/chromium/issues/detail?id=954160#c5
https://github.com/envoyproxy/envoy/issues/6767
https://github.com/istio/istio/issues/13589
https://github.com/istio/istio/issues/9429

Comment 4 Mark Cooper 2020-09-11 08:35:41 UTC

External References:

https://github.com/envoyproxy/envoy/issues/6767

Comment 6 Mark Cooper 2021-10-28 02:04:42 UTC

closing old flaw bug