CVE-2017-15727 in phpMyFAQ
Summary
by MITRE
In phpMyFAQ before 2.9.9, there is Stored Cross-site Scripting (XSS) via an HTML attachment.
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Analysis
by VulDB Data Team • 10/30/2025
The vulnerability identified as CVE-2017-15727 represents a critical stored cross-site scripting flaw in phpMyFAQ versions prior to 2.9.9, where malicious actors can inject persistent malicious scripts through HTML attachments. This vulnerability resides in the application's handling of user-uploaded content, specifically within the attachment processing mechanism that fails to properly sanitize or escape HTML content before storing and rendering it in subsequent user interactions.
The technical implementation of this vulnerability occurs when phpMyFAQ processes HTML attachments without adequate input validation or output encoding, allowing attackers to embed malicious script code within attachment metadata or content. When legitimate users subsequently view these attachments, the stored scripts execute in their browser context, potentially enabling session hijacking, credential theft, or redirection to malicious sites. The flaw demonstrates characteristics consistent with CWE-79 - Improper Neutralization of Input During Web Page Generation, where user-controllable data is directly incorporated into web pages without proper sanitization.
The operational impact of this vulnerability extends beyond simple script execution, as it can be leveraged for more sophisticated attacks within the phpMyFAQ environment. An attacker who gains the ability to upload malicious HTML attachments can potentially compromise user sessions through session cookie theft, redirect users to phishing sites, or execute arbitrary JavaScript in the context of the vulnerable application. This vulnerability particularly affects environments where multiple users interact with the phpMyFAQ system and where attachment uploads are permitted, creating a persistent threat vector that remains active until the system is patched.
Security professionals should consider this vulnerability in the context of broader ATT&CK framework techniques, specifically T1566 - Phishing and T1059 - Command and Scripting Interpreter, as it enables attackers to establish persistent malicious presence through legitimate user interactions. The remediation strategy should focus on implementing proper input validation and output encoding mechanisms, including HTML sanitization of all user-uploaded content, enforcement of strict content type restrictions, and comprehensive testing of attachment handling functionality. Organizations should also consider implementing web application firewalls and monitoring for suspicious attachment uploads as additional defensive measures.