Users with capabilities to upload media (editors and above) are succeptible to SSRF (Server-Side Request Forgery) when executing the createMediaItem Mutation.
It's recommended to update to WPGraphQL v1.14.6 or newer. If you're unable to do so, below is a snippet you can add to your functions.php (or similar) that filters the createMediaItem mutation's resolver.
If you're unable to upgrade to v1.14.6 or higher, you should be able to use the following snippet in your functions.php to override the vulnerable resolver.
add_filter( 'graphql_pre_resolve_field', function( $nil, $source, $args, $context, \GraphQL\Type\Definition\ResolveInfo $info, $type_name, $field_key, $field, $field_resolver ) {
if ( $info->fieldName !== 'createMediaItem' ) {
return $nil;
}
$input = $args['input'] ?? null;
if ( ! isset( $input['filePath'] ) ) {
return $nil;
}
$uploaded_file_url = $input['filePath'];
// Check that the filetype is allowed
$check_file = wp_check_filetype( $uploaded_file_url );
// if the file doesn't pass the check, throw an error
if ( ! $check_file['ext'] || ! $check_file['type'] || ! wp_http_validate_url( $uploaded_file_url ) ) {
throw new \GraphQL\Error\UserError( sprintf( __( 'Invalid filePath "%s"', 'wp-graphql' ), $input['filePath'] ) );
}
$protocol = wp_parse_url( $input['filePath'], PHP_URL_SCHEME );
// prevent the filePath from being submitted with a non-allowed protocols
$allowed_protocols = [ 'https', 'http', 'file' ];
if ( ! in_array( $protocol, $allowed_protocols, true ) ) {
throw new \GraphQL\Error\UserError( sprintf( __( 'Invalid protocol. "%1$s". Only "%2$s" allowed.', 'wp-graphql' ), $protocol, implode( '", "', $allowed_protocols ) ) );
}
return $nil;
}, 10, 9 );
Impact
Users with capabilities to upload media (editors and above) are succeptible to SSRF (Server-Side Request Forgery) when executing the
createMediaItemMutation.Authenticated users making GraphQL requests that execute the
createMediaItemcould pass executable paths in the mutationsfilePathargument that could give them unwarranted access to the server.It's recommended to update to WPGraphQL v1.14.6 or newer. If you're unable to do so, below is a snippet you can add to your functions.php (or similar) that filters the
createMediaItemmutation's resolver.Patches
Workarounds
If you're unable to upgrade to v1.14.6 or higher, you should be able to use the following snippet in your functions.php to override the vulnerable resolver.
This snippet has been tested as far back as WPGraphQL v0.15
References