Bug 1232302 (CVE-2015-3227)

Summary: CVE-2015-3227 rubygem-activesupport: Possible Denial of Service attack in Active Support in merge_element()
Product: [Other] Security Response Reporter: Vasyl Kaigorodov <vkaigoro>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED WONTFIX QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: apatters, bkearney, carnil, cbillett, ccoleman, dajohnso, dclarizi, dmcphers, gmccullo, jhardy, jialiu, joelsmith, jokerman, jorton, jprause, jrafanie, jrusnack, jvlcek, kseifried, lmeyer, mmaslano, mmccomas, obarenbo, security-response-team, tomckay, vondruch, xlecauch
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: rubygem-activesupport-4.2.2, rubygem-activesupport-4.1.11 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-07-31 12:56:31 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: 1249062, 1249063, 1249064, 1249065, 1249066    
Bug Blocks: 1232306    
Attachments:
Description Flags
Patch for ActiveSupport 3.2
none
Patch for ActiveSupport 4.1
none
Patch for ActiveSupport 4.2 none

Description Vasyl Kaigorodov 2015-06-16 13:00:48 UTC 
A possible denial of service attack in the XML processing in Active Support has been reported.

Specially crafted XML documents can cause applications to raise a
`SystemStackError` and potentially cause a denial of service attack.  This
only impacts applications using REXML or JDOM as their XML processor.  Other
XML processors that Rails supports are not impacted.

Workarounds 
----------- 
Use an XML parser that is not impacted by this problem, such as Nokogiri or
LibXML.  You can change the processor like this:

  ActiveSupport::XmlMini.backend = 'Nokogiri'

  If you cannot change XML parsers, then adjust
  `RUBY_THREAD_MACHINE_STACK_SIZE`.

Patches that fix this issue attached.

Acknowledgements:

Red Hat would like to thank the Ruby upstream developers for reporting this issue. Upstream acknowledges Tomek Rabczak from the NCC Group, and Matthew Draper as the original reporters.
Comment 1 Kurt Seifried 2015-06-16 19:37:54 UTC 
This is now public:

http://seclists.org/oss-sec/2015/q2/731
Comment 2 Ján Rusnačko 2015-07-31 12:42:27 UTC 
Created attachment 1058046 [details]
Patch for ActiveSupport 3.2
Comment 3 Ján Rusnačko 2015-07-31 12:42:48 UTC 
Created attachment 1058047 [details]
Patch for ActiveSupport 4.1
Comment 4 Ján Rusnačko 2015-07-31 12:43:11 UTC 
Created attachment 1058049 [details]
Patch for ActiveSupport 4.2
Comment 7 Ján Rusnačko 2015-07-31 12:50:26 UTC 
Created rubygem-activesupport tracking bugs for this issue:

Affects: fedora-all [bug 1249062]
Affects: epel-all [bug 1249063]