The vulnerability in phpMyFAQ 2.9.8 is a Cross-Site Request Forgery (CSRF) flaw affecting the glossary modification functionality (add, update, delete). Prior to patching, the application did not implement CSRF token validation for these actions, allowing an attacker to craft malicious web pages that, when visited by an authenticated user with the 'editglossary' permission, would automatically submit POST requests to update glossary entries. The attack requires the victim to be logged into the phpMyFAQ admin interface and have sufficient privileges. The exploit works by embedding a hidden HTML form targeting the URL 'http://phpmyfaq/admin/index.php?action=updateglossary' with parameters 'id', 'item', and 'definition' set to attacker-controlled values. A JavaScript snippet auto-submits the form, executing the unauthorized action without user consent. The file navigation chain involves 'index.php' routing to 'glossary.main.php' and 'glossary.edit.php', where the glossary update logic resides. The patch introduced CSRF token checks for both POST and GET requests to ensure that only legitimate sessions can perform glossary modifications. This vulnerability is identified as CVE-2017-15735 and has publicly available proof-of-concept exploit code. Although no widespread exploitation has been reported, the vulnerability poses a risk to the integrity of FAQ content and could be leveraged for misinformation or defacement within affected installations.

For European organizations using phpMyFAQ 2.9.8, this CSRF vulnerability can lead to unauthorized modification of glossary entries, undermining the integrity and reliability of internal knowledge bases. This could result in misinformation being disseminated among employees or customers, potentially causing operational confusion or reputational damage. While the vulnerability does not allow privilege escalation or data exfiltration, the ability to alter content without authorization compromises data integrity and trust. Organizations relying on phpMyFAQ for critical documentation or customer support may face increased risk of social engineering or misinformation attacks. The requirement for the attacker to have the victim authenticated limits the scope but does not eliminate risk, especially in environments where users frequently access the admin interface. Additionally, automated exploitation via malicious web pages could target multiple users simultaneously. The impact on availability is minimal, but integrity and confidentiality of the FAQ content are at risk.

Organizations should immediately upgrade phpMyFAQ installations to versions that include the patch for CVE-2017-15735, which implements CSRF token validation for glossary modification actions. If upgrading is not immediately feasible, administrators should implement compensating controls such as restricting access to the admin interface via network segmentation or VPN, enforcing strict session timeouts, and educating users about the risks of visiting untrusted websites while authenticated. Web application firewalls (WAFs) can be configured to detect and block suspicious POST requests lacking valid CSRF tokens. Additionally, reviewing and minimizing the number of users with 'editglossary' permissions reduces the attack surface. Regular audits of glossary content can help detect unauthorized changes early. Finally, enabling multi-factor authentication (MFA) for admin accounts adds an extra layer of security against session hijacking that could facilitate CSRF attacks.