Xerces-C++: Denial of service

Background

Xerces-C++ is a validating XML parser written in a portable subset of C++.

Description

Frank Rast reported that the XML parser in Xerces-C++ does not correctly handle an XML schema definition with a large maxOccurs value, which triggers excessive memory consumption during the validation of an XML file.

Impact

A remote attacker could entice a user or automated system to validate an XML file using a specially crafted XML schema file, leading to a Denial of Service (stack consumption and crash).

Workaround

There is no known workaround at this time.

Resolution

All Xerces-C++ users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=dev-libs/xerces-c-3.0.0-r1"