sparkweb

This plugin lets you edit the custom fields for many posts at once. Designed to work with pages, posts, and all custom post types. The plugin also has some actions included so that plugins and themes can integrate seamlessly and build their own extensions into the functionality.

Custom Field Bulk Editor

This plugin lets you edit the custom fields for many posts at once. Designed to work with pages, posts, and all custom post types.

Ruslan Mikhno

This is a very simple plugin that allows you to bulk change author for media files.
The action is added in the “List” view of the Media Library.

Bulk Change Media Author

Bulk change author for multiple media files, using the default WP Media Library.

Custom Field Bulk Editor vs Bulk Change Media Author