phpMyAdmin is a tool written in PHP intended to handle the administration of MySQL databases from a web-browser.
Cezary Tomczak reported that an undefined UploadDir variable exposes an information disclosure vulnerability when running on shared hosts.
A remote attacker with CREATE TABLE permissions can exploit this vulnerability via a specially crafted HTTP POST request in order to read arbitrary files.
There is no known workaround at this time.
All phpMyAdmin users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-db/phpmyadmin-2.11.5.2"