Bug 1336350 (CVE-2016-1546)

Summary:	CVE-2016-1546 httpd: mod_http2 denial-of-service by thread starvation
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bbaranow, bmaxwell, cdewolf, cpelland, csutherl, dajohnso, dandread, darran.lofthouse, dknox, fnasser, gblomqui, gmccullo, gtanzill, hhudgeon, huwang, jason.greene, jawilson, jboss-set, jclere, jdoyle, jfrey, jhardy, jhouska, jkaluza, jorton, jprause, jrafanie, lgao, mbabacek, mmaslano, myarboro, obarenbo, pahan, pgier, psakar, pslavice, rmeggins, rnetuka, roliveri, rsvoboda, sardella, twalsh, vtunka, webstack-team, weli
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	httpd 2.4.20	Doc Type:	Bug Fix
Doc Text:	A denial of service flaw was found in httpd's mod_http2 module. A remote attacker could use this flaw to block server threads for long times, causing starvation of worker threads, by manipulating the flow control windows on streams.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:51:54 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:	1336351, 1425470
Bug Blocks:	1336352

Description Andrej Nemec 2016-05-16 08:54:19 UTC

A vulnerability was found in httpd. By manipulating the flow control windows on streams, a client was able to block server threads for long times, causing starvation of worker threads. Connections could still be opened, but no streams where processed for these. This issue affected HTTP/2 support in 2.4.17 and 2.4.18.

External references:

http://httpd.apache.org/security/vulnerabilities_24.html

Comment 1 Andrej Nemec 2016-05-16 08:54:46 UTC

Created httpd tracking bugs for this issue:

Affects: fedora-all [bug 1336351]

Comment 2 Tomas Hoger 2016-05-16 11:39:22 UTC

Upstream commit:

http://svn.apache.org/viewvc?view=revision&revision=1733727

Backported to 2.4.x branch via:

http://svn.apache.org/viewvc?view=revision&revision=1734413

Included in 2.4.19, which was not released.

Comment 5 errata-xmlrpc 2017-04-26 10:22:06 UTC

This issue has been addressed in the following products:

  Red Hat Software Collections for Red Hat Enterprise Linux 6
  Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS
  Red Hat Software Collections for Red Hat Enterprise Linux 7
  Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS

Via RHSA-2017:1161 https://access.redhat.com/errata/RHSA-2017:1161