Bug 518215 (CVE-2009-2473)

Summary: CVE-2009-2473 neon: billion laughs DoS attack
Product: [Other] Security Response Reporter: Jan Lieskovsky <jlieskov>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: jorton, kreilly, tbzatek, vdanen
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
URL: http://lists.manyfish.co.uk/pipermail/neon/2009-August/001045.html
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-01-08 06:08:39 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: 521786, 521787, 521788, 521789, 540548, 795936    
Bug Blocks:    
Attachments:
Description Flags
Upstream Neon CVE-2009-2473 patch none

Description Jan Lieskovsky 2009-08-19 14:33:34 UTC
Neon, before 0.28.6, does not properly detect recursion during
XML entity expansion, which allows context-dependent attackers to 
cause a denial of service (memory and CPU consumption) via a crafted
XML document containing a large number of nested entity references,
aka the "billion laughs attack."

References:
-----------
http://lists.manyfish.co.uk/pipermail/neon/2009-August/001044.html
http://lists.manyfish.co.uk/pipermail/neon/2009-August/001045.html

Comment 1 Jan Lieskovsky 2009-08-19 14:35:28 UTC
Information about affected Neon versions from Joe Orton:
-------------------------------------------------------

All versions of neon older than 0.28.6 are affected, where linked 
against expat.  This issue does not affect versions of neon which are 
compiled to use libxml2 instead of expat, provided the libxml2 version 
is 2.6.32 or greater.

Comment 2 Jan Lieskovsky 2009-08-19 15:06:57 UTC
Created attachment 357950 [details]
Upstream Neon CVE-2009-2473 patch

Retrieved via:
--------------

   svn diff -c 1688 http://svn.webdav.org/repos/projects/neon/tags/0.28.6 > neon-CVE-2009-2473.patch

Comment 4 Jan Lieskovsky 2009-08-22 08:26:53 UTC
MITRE's CVE-2009-2473 record:
-----------------------------

neon before 0.28.6, when expat is used, does not properly detect
recursion during entity expansion, which allows context-dependent
attackers to cause a denial of service (memory and CPU consumption)
via a crafted XML document containing a large number of nested entity
references, a similar issue to CVE-2003-1564.

References:
-----------
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2473
http://lists.manyfish.co.uk/pipermail/neon/2009-August/001045.html
http://lists.manyfish.co.uk/pipermail/neon/2009-August/001044.html
https://www.redhat.com/archives/fedora-package-announce/2009-August/msg00924.html
https://www.redhat.com/archives/fedora-package-announce/2009-August/msg00945.html
http://secunia.com/advisories/36371

Comment 8 Jan Lieskovsky 2009-09-08 11:18:19 UTC
Update availability information for embedded copy
of neon package as present in gnome-vfs2 package:
-------------------------------------------------

The Red Hat Security Response Team has rated this issue
as having low security impact, a future gnome-vfs2 package 
update may address this flaw in Red Hat Enterprise Linux 4
and Red Hat Enterprise Linux 5. More information regarding
issue severity can be found here:
http://www.redhat.com/security/updates/classification/

Comment 9 errata-xmlrpc 2009-09-21 15:19:19 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5
  Red Hat Enterprise Linux 4

Via RHSA-2009:1452 https://rhn.redhat.com/errata/RHSA-2009-1452.html

Comment 14 errata-xmlrpc 2013-01-08 05:14:25 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2013:0131 https://rhn.redhat.com/errata/RHSA-2013-0131.html