PEAR::MDB2 is a database abstraction layer for PHP aimed to provide a common API for all supported relational database management systems. A LOB ("large object") is a database field holding binary data.
priyadi discovered that the request to store a URL string as a LOB is treated as a request to retrieve and store the contents of the URL.
If an application using PEAR::MDB2 allows input of LOB values via a web form, remote attackers could use the application as an indirect proxy or obtain sensitive information, including "file://" URLs local to the web server.
As a workaround, manually filter input before storing it as a LOB in PEAR::MDB2.
All PEAR::MDB2 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-php/PEAR-MDB2-2.5.0_alpha1"