Bug 787109 (CVE-2012-0877)

Summary:	CVE-2012-0877 PyXML: hash table collisions CPU usage DoS (oCERT-2011-003)
Product:	[Other] Security Response	Reporter:	Kurt Seifried <kseifried>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	apevec, cpelland, jrusnack, mburns, rbalakri, security-response-team, tsmetana
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-01-17 04:45:23 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:
Bug Blocks:	770929, 782164

Description Kurt Seifried 2012-02-03 07:28:57 UTC

However upstream PyXML will still be affected

Juraj Somorovsky reported that certain XML parsers/servers are affected by the
same, or similar, flaw as the hash table collisions CPU usage denial of
service.  Sending a specially crafted message to an XML service can result in
longer processing time, which could lead to a denial of service.  It is
reported that this attack on XML can be applied on different XML nodes (such as
entities, element attributes, namespaces, various elements in the XML security,
etc.).

PyXML is written in Python and makes significant use of arrays. It is unclear if fixing the Python array hash DoS bug (Bz 750555) will completely address this issue however at first glance it would appear to be the case. In other words no action should be neccesary from upstream to correct this.

Additionally our PyXML uses the system expat (from the spec file):

# build PyXML with system expat
# Make sure we don't use local one

which is covered in bug: 787080

Comment 1 Kurt Seifried 2012-02-03 07:31:17 UTC

Packages that require PyXML:

SOAPpy-0.11.6-11
subscription-manager-0.96.12-1

Comment 6 Kurt Seifried 2015-01-17 04:45:23 UTC

Statement:

This issue affects the versions of xerces as shipped with Red Hat Enterprise Linux 6. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.