The PEAR XML-RPC and phpxmlrpc libraries are both PHP implementations of the XML-RPC protocol.
Stefan Esser of the Hardened-PHP Project discovered that the PEAR XML-RPC and phpxmlrpc libraries were improperly handling XMLRPC requests and responses with malformed nested tags.
A remote attacker could exploit this vulnerability to inject arbitrary PHP script code into eval() statements by sending a specially crafted XML document to web applications making use of these libraries.
There are no known workarounds at this time.
All PEAR-XML_RPC users should upgrade to the latest available version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-php/PEAR-XML_RPC-1.4.0"
All phpxmlrpc users should upgrade to the latest available version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-php/phpxmlrpc-1.2-r1"