Bug 1379553 – CVE-2016-9180 perl-XML-Twig: expand_external_ents option fails to work as documented

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Bug 1379553 - (CVE-2016-9180) CVE-2016-9180 perl-XML-Twig: expand_external_ents option fails to work as documented

Summary:	CVE-2016-9180 perl-XML-Twig: expand_external_ents option fails to work as do...

Status:	CLOSED WONTFIX

Aliases:	CVE-2016-9180

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	medium Severity medium
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=moderate,public=20160927,repor...
Keywords:	Security

Depends On:	1379554
Blocks:	1377998
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Reported:	2016-09-27 02:49 EDT by Doran Moppert
Modified:	2017-07-26 10:20 EDT (History)
CC List:	8 users (show)

See Also:
Fixed In Version:
Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in perl-XML-Twig. External entity expansion (XXE) took place regardless of the setting 'expand_external_ents', which was supposed to disable this functionality if set to 0 (the default) or -1. An attacker could craft an XML message which, when processed by an application using perl-XML-Twig, could cause denial of service or, potentially, information disclosure.
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Last Closed:	2016-11-16 21:47:08 EST
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
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oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
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Description Doran Moppert 2016-09-27 02:49:56 EDT

The option to `expand_external_ents`, documented as controlling external entity
expansion in XML::Twig does not work.  External entities are always expanded,
regardless of the option's setting.

Upstream bug:

https://rt.cpan.org/Public/Bug/Display.html?id=118097

Comment 1 Doran Moppert 2016-09-27 02:52:24 EDT

Created perl-XML-Twig tracking bugs for this issue:

Affects: fedora-all [bug 1379554]

Comment 2 Doran Moppert 2016-11-16 20:34:02 EST

Statement:

Red Hat Product Security has rated this issue as having Moderate 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/.

Comment 3 Doran Moppert 2016-11-16 20:34:09 EST

Acknowledgments:

Name: Doran Moppert (Red Hat Product Security Team)

Comment 4 Petr Pisar 2017-07-26 10:20:32 EDT

Upstream released 3.50 that added no_xxe flag that implements the desired behavior, but expand_external_ents flag, subject of this vulnerability, still has no effect.

So while XML-Twig >= 3.50 can now be used safely, the reported bug still exists.

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