Bug 1896120 (CVE-2017-18926)

Summary:	CVE-2017-18926 raptor: heap-based buffer overflows due to an error in calculating the maximum nspace declarations for the XML writer
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	caolanm, fweimer, green, jgrulich, jskarvad, kde-sig, rdieter
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
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Clone Of:		Environment:
Last Closed:	2021-05-18 20:37:06 UTC	Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1896534
Bug Blocks:	1896121

Description Guilherme de Almeida Suckevicz 2020-11-09 19:00:46 UTC

raptor_xml_writer_start_element_common in raptor_xml_writer.c in Raptor RDF Syntax Library 2.0.15 miscalculates the maximum nspace declarations for the XML writer, leading to heap-based buffer overflows (sometimes seen in raptor_qname_format_as_xml).

Reference:
https://www.openwall.com/lists/oss-security/2017/06/07/1

Upstream patch:
https://github.com/LibreOffice/core/blob/master/external/redland/raptor/0001-Calcualte-max-nspace-declarations-correctly-for-XML-.patch.1

Comment 3 Todd Cullum 2020-11-10 20:14:21 UTC

Flaw summary:

When raptor2 processes a crafted input file, it could execute a heap-buffer-overflow -> out-of-bounds write due to improper calculation of `nspace_max_count` in raptor_xml_writer.c. In the context of RHEL-8, this library is used by libreoffice to parse files. If it were affected, an attacker who could social engineer a victim into opening a crafted file could trigger this flaw and impact application availability or in more rare circumstances, data integrity. However, libreoffice shipped with RHEL-8 has already been patched and thus libreoffice is notaffected.

Comment 4 Todd Cullum 2020-11-10 20:26:02 UTC

Upstream patch in raptor (aforementioned patch is in LibreOffice): https://github.com/dajobe/raptor/commit/590681e546cd9aa18d57dc2ea1858cb734a3863f

Comment 5 Todd Cullum 2020-11-10 20:29:25 UTC

Statement:

LibreOffice as shipped with Red Hat Enterprise Linux 8 is notaffected by this flaw as the version of raptor used in LibreOffice already has the patch.

Comment 9 errata-xmlrpc 2021-05-18 15:30:44 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1842 https://access.redhat.com/errata/RHSA-2021:1842

Comment 10 Product Security DevOps Team 2021-05-18 20:37:06 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2017-18926