AdminNeo SQLite Database-List Drop Arbitrary File Deletion

Summary#

AdminNeo allows an authenticated SQLite-mode user to delete arbitrary files writable by the PHP process through the database-list drop action. The SQLite driver validates file extensions when creating or renaming databases, but the database-list drop path passes submitted db[] values directly to unlink().

Originally reported by @slpoiuewalspoid-dotcom in Adminer: https://github.com/vrana/adminer/security/advisories/GHSA-6pg3-chwq-wgqc

Impact#

An authenticated AdminNeo SQLite user with a valid CSRF token can submit an arbitrary relative file path in the database-list db[] field. If the PHP process can delete that path, AdminNeo unlinks it even when the file is not a SQLite database.

Root Cause#

The database-list page accepts selected database names from the POST body and calls drop_databases():

if ($_POST["db"]) {
	queries_redirect(substr(ME, 0, -1), lang('Databases have been dropped.'), drop_databases($_POST["db"]));
}

In SQLite mode, drop_databases() attaches an in-memory database and unlinks each submitted path directly:

function drop_databases($databases): bool
{
	Connection::get()->close(); // to unlock file, doesn't work in PDO on Windows
	foreach ($databases as $db) {
		if (!@unlink($db)) {
			Connection::get()->setError(lang('File exists.'));
			return false;
		}
	}
	return true;
}

The same SQLite driver protects create and rename operations with check_sqlite_name(), which requires a .db, .sdb, or .sqlite extension:

function check_sqlite_name($name) {
	// avoid creating PHP files on unsecured servers
	$extensions = "db|sdb|sqlite";
	if (!preg_match("~^[^\\0]*\\.($extensions)\$~", $name)) {
		Connection::get()->setError(lang('Please use one of the extensions %s.', str_replace("|", ", ", $extensions)));
		return false;
	}
	return true;
}

The drop path does not apply an equivalent extension check or bind the submitted path to a known listed SQLite database.

POC#

1. Start a complete AdminNeo application#

Build and start AdminNeo from the audited source using the official standalone Docker image shape. The validation image copies the audited source tree into /var/www/html and starts Nginx HTTP server.

Log in through the SQLite entry point using a SQLite database path poc.sqlite.

2. Prepare a writable target file#

Place a non-database file under a location writable by the AdminNeo PHP process. The validation used:

/var/www/html/poc-delete-target.txt

The same directory also contained a SQLite database:

/var/www/html/poc.sqlite

3. Submit the database-list drop request#

Use the authenticated session and live CSRF token, but submit the non-database path as the selected database:

POST /?sqlite=&username= HTTP/1.1
Host: <adminer-host>
Cookie: <authenticated-session>
Content-Type: application/x-www-form-urlencoded

db[]=/var/www/html/poc-delete-target.txt&all=&drop=Drop&token=<live-csrf-token>

The request reaches drop_databases($_POST["db"]), and SQLite drop_databases() calls unlink() on the submitted non-database path.

After the request, the poc-delete-target.txt was deleted.

Suggested Fix#

Apply the same target validation used by SQLite create/rename before deleting database files. At minimum:

• Reject paths whose basename does not end in .db, .sdb, or .sqlite.
• Bind db[] values to databases returned by AdminNeo's database listing instead of trusting submitted paths.
• Resolve paths before deletion and reject traversal outside the expected SQLite database directory.
• Consider requiring the current selected database path for delete operations instead of accepting arbitrary submitted file paths.