Bug 1473720 (CVE-2017-11465)

Summary:	CVE-2017-11465 ruby: Invalid read/write in parser_yyerror function in UTF-8 parser
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	bkearney, cbillett, ccoleman, cpelland, dajohnso, dclarizi, dedgar, dmcphers, gblomqui, gmccullo, gtanzill, hhorak, hhudgeon, jfrey, jgoulding, jhardy, jorton, jprause, kseifried, mmorsi, mtasaka, obarenbo, roliveri, ruby-maint, simaishi, s, strzibny, tomckay, vanmeeuwen+fedora, vondruch
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-22 13:40:46 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:	1473721
Bug Blocks:	1473724

Description Adam Mariš 2017-07-21 13:46:58 UTC

The parser_yyerror function in the UTF-8 parser in Ruby 2.4.1 allows attackers to cause a denial of service (invalid write or read) or possibly have unspecified other impact via a crafted Ruby script, related to the parser_tokadd_utf8 function in parse.y. NOTE: this might have security relevance as a bypass of a $SAFE protection mechanism.

Upstream bug:

https://bugs.ruby-lang.org/issues/13742

Comment 1 Adam Mariš 2017-07-21 13:47:34 UTC

Created ruby tracking bugs for this issue:

Affects: fedora-all [bug 1473721]

Comment 2 Vít Ondruch 2017-07-24 09:07:17 UTC

This is not vulnerability according to upstream [1]:

~~~
Note that this is not a vulnerability.
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-11465 is invalid.
~~~

[1] https://bugs.ruby-lang.org/issues/13742#note-3

Comment 3 Stefan Cornelius 2017-07-25 09:42:39 UTC

Patch:
https://github.com/ruby/ruby/commit/80d502b88116e95e4b17b4e7278d0d47106253db

Possibly also relevant:
https://github.com/ruby/ruby/commit/f29e5013adcd9c8753587471727e3280aaf89686#diff-6d840db07406437770b610102b284273

Comment 4 Stefan Cornelius 2017-07-25 10:01:09 UTC

Lowering impact because this is disputed upstream. Unfortunately, I've not been able to reproduce this issue myself yet, so I can't say if the dispute is correct.

Comment 5 Stefan Cornelius 2017-08-22 13:41:02 UTC

Statement:

Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.

Additionally, the security impact of this flaw is disputed by the upstream Ruby project.