Bug 1334786 (CVE-2016-4556)

Summary:	CVE-2016-4556 squid: SIGSEGV in ESIContext response handling
Product:	[Other] Security Response	Reporter:	Cedric Buissart <cbuissar>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	admiller, dvlasenk, luhliari, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	An incorrect reference counting flaw was found in the way Squid processes ESI responses. If Squid is configured as reverse-proxy, for TLS/HTTPS interception, an attacker controlling a server accessed by Squid, could crash the squid worker, causing a Denial of Service attack.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-06-09 12:43:47 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:	1334489, 1334490, 1334491, 1334492, 1334499, 1334500, 1334787
Bug Blocks:	1334247

Description Cedric Buissart 2016-05-10 14:18:33 UTC

Due to incorrect reference counting Squid is vulnerable to a denial of service attack when processing ESI responses.

External references:

http://www.squid-cache.org/Advisories/SQUID-2016_9.txt

Upstream fixes:

Squid 3.5:

http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2016_9.patch

Squid 3.4:

http://www.squid-cache.org/Versions/v3/3.4/changesets/SQUID-2016_9.patch

NOTE: 
For the other related CVE, CVE-2016-4555, see Bug 1334246

Comment 1 Cedric Buissart 2016-05-10 14:19:03 UTC

Created busybox tracking bugs for this issue:

Affects: fedora-all [bug 1334787]

Comment 4 errata-xmlrpc 2016-05-31 05:43:44 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:1139 https://access.redhat.com/errata/RHSA-2016:1139

Comment 5 errata-xmlrpc 2016-05-31 05:57:26 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2016:1140 https://access.redhat.com/errata/RHSA-2016:1140

Comment 6 errata-xmlrpc 2016-05-31 05:58:06 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2016:1138 https://access.redhat.com/errata/RHSA-2016:1138