Inclusion of Sensitive Information in Source Code

Description

There are situations where it is critical to remove source code from an area or server. For example, obtaining Perl source code on a system allows an attacker to understand the logic of the script and extract extremely useful information such as code bugs or logins and passwords.

Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

The following code uses an include file to store database credentials:

database.inc

<?php
$dbName = 'usersDB';
$dbPassword = 'skjdh#67nkjd3$3$';
?>

login.php

<?php
include('database.inc');
$db = connectToDB($dbName, $dbPassword);
$db.authenticateUser($username, $password);
?>

If the server does not have an explicit handler set for .inc files it may send the contents of database.inc to an attacker without pre-processing, if the attacker requests the file directly. This will expose the database name and password.

Example Two

The following comment, embedded in a JSP, will be displayed in the resulting HTML output.

<!-- FIXME: calling this with more than 30 args kills the JDBC server -->

See Also