CVE-2024-22208 is a medium-severity vulnerability classified under CWE-863 (Incorrect Authorization) affecting phpMyFAQ, an open-source FAQ web application supporting PHP 8.1+ and multiple database backends such as MySQL and PostgreSQL. The vulnerability arises from the 'sharing FAQ' functionality, which allows users to share FAQ items via email to up to five recipients. However, the backend does not enforce this limit, permitting an unauthenticated attacker to bypass the front-end restriction and send emails to an unlimited number of recipients after solving a single CAPTCHA. This flaw enables attackers to leverage the phpMyFAQ application's email server to send large volumes of arbitrary emails, potentially including phishing messages. The exploitation does not require authentication or multiple CAPTCHA solves, making it easier to automate and scale. The consequences include the risk of the server being blacklisted by email providers, resulting in legitimate emails being marked as spam, damaging the organization's email reputation and trustworthiness. Additionally, it can facilitate phishing campaigns that may compromise users or internal systems. The vulnerability affects phpMyFAQ versions prior to 3.2.5, where the issue has been patched. The CVSS v3.1 base score is 6.5, reflecting a medium severity with network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to integrity and availability but not confidentiality.

For European organizations using phpMyFAQ versions earlier than 3.2.5, this vulnerability presents a significant risk to email infrastructure and organizational reputation. Exploitation can lead to mass unsolicited emails originating from trusted internal servers, increasing the likelihood of blacklisting by major European and global email providers such as Deutsche Telekom, Orange, BT, and others. This can disrupt legitimate business communications, delay critical information exchange, and degrade customer trust. Furthermore, phishing campaigns sent via compromised phpMyFAQ instances can target European employees or customers, potentially leading to credential theft, fraud, or malware infections. The impact on availability is moderate, as email services may be throttled or blocked. Integrity is affected due to unauthorized use of the email system to send malicious content. Confidentiality is not directly impacted. Organizations in sectors with high reliance on email communications, such as finance, healthcare, and government agencies within Europe, face elevated risks. The vulnerability also poses reputational damage risks, which are particularly sensitive under European data protection regulations and compliance frameworks.

European organizations should immediately verify their phpMyFAQ version and upgrade to version 3.2.5 or later where the vulnerability is patched. If upgrading is not immediately feasible, organizations should implement strict rate limiting on the email sharing functionality at the backend to enforce the five-recipient limit per request. Additionally, enhancing CAPTCHA mechanisms to prevent automated solving or integrating multi-factor verification can reduce abuse. Monitoring outgoing email traffic for unusual volumes or patterns originating from phpMyFAQ servers is critical to detect exploitation attempts early. Organizations should also configure email servers with SPF, DKIM, and DMARC policies to mitigate phishing risks and improve email deliverability. Blacklist monitoring services should be employed to quickly identify if the mail server is flagged. Finally, restricting access to the phpMyFAQ sharing feature to authenticated users or trusted IP ranges can reduce exposure. Regular security audits and penetration testing focusing on web application authorization controls are recommended to prevent similar issues.