It was found that the optional PostgreSQL xml2 contrib module allowed local files and remote URLs to be read and written to with the privileges of the database server when parsing Extensible Stylesheet Language Transformations . An unprivileged database user could use this flaw to read and write to local files and remote URLs they would otherwise not have access to by issuing a specially-crafted SQL query. It was found that the "xml" data type allowed local files and remote URLs to be read with the privileges of the database server to resolve DTD and entity references in the provided XML. An unprivileged database user could use this flaw to read local files they would otherwise not have access to by issuing a specially-crafted SQL query. Note that the full contents of the files were not returned, but portions could be displayed to the user via error messages