Andrew van der Stock (of OWASP fame) wrote his own secure forum software as well: http://www.ultimabb.com/

PunBB, SMF (Simple Machines), and Vanilla also have very good reputations for free forum software.

For web-anything, I normally suggest JSPWiki (or something very similar) fronted by mod_security. I’d like to see JSPWiki or something very similar re-written in HDIV Struts with proper use of Validator everywhere.

The most important aspect is to keep your fourm software up-to-date, especially after known vulnerabilities are released into the public.

I’m posting the bb-login.php file :

< ?php
require('./bb-load.php');

$ref = wp_get_referer();

if ( 0 === strpos($ref, bb_get_option( 'uri' )) ) {
$re = $_POST['re'] ? $_POST['re'] : $_GET['re'];
if ( 0 !== strpos($re, bb_get_option( 'uri' )) )
$re = $ref . $re;
} else
$re = bb_get_option('uri');

nocache_headers();

if ( isset( $_REQUEST['logout'] ) ) {
bb_logout();
wp_redirect( $re );
exit;
}

if ( !bb_is_user_logged_in() && !$user = bb_login( @$_POST['user_login'], @$_POST['password'] ) ) {
$user_exists = bb_user_exists( @$_POST['user_login'] );
$user_login = user_sanitize ( @$_POST['user_login'] );
$redirect_to = wp_specialchars( $re, 1 );
bb_load_template( 'login.php', array('re', 'user_exists', 'user_login', 'redirect_to', 'ref') );
exit;
}

wp_redirect( $re );
?>

The user_sanitize function permits only a-z A-Z and 0-9 , so no luck with the username string.
The $re parameter is appended to the current URL and although it seems an easy catch for a forceful redirect, the appended string starts with / which sucks .

So please let me know which vulnerability have you spotted . Please email me (dragos@dragoslungu.com) or post it here and I will edit the post to reflect your findings.

I would really appreciate .

Hold the press - from a 2 minutes review of BBPress (which in your research yielded 0 vulnerabilities), I can already tell you that the login page contains a XSS vulnerability. (I am talking about the latest version of BBPress here).

Check out the source code of bb-login.php, and you’ll figure it out. (it’s exploitable).
Bottom line, I haven’t seen a single BB app lately, that doesn’t contain any vulnerabilities

Hope this helps,
-Ory Segal