CVE-2018-18671 in GNUBOARD5
Summary
by MITRE
GNUBOARD5 5.3.1.9 has XSS that allows remote attackers to inject arbitrary web script or HTML via the "mobile board head contents" parameter, aka the adm/board_form_update.php bo_mobile_content_head parameter.
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Analysis
by VulDB Data Team • 09/19/2024
GNUBOARD5 version 5.3.1.9 contains a cross-site scripting vulnerability that enables remote attackers to inject malicious web scripts or HTML code through the "mobile board head contents" parameter. This vulnerability specifically affects the adm/board_form_update.php endpoint where the bo_mobile_content_head parameter is processed without adequate input validation or output sanitization. The flaw represents a classic reflected cross-site scripting issue where user-supplied data is directly incorporated into the web page response without proper encoding or filtering mechanisms. Attackers can exploit this vulnerability by crafting malicious payloads in the mobile board head contents field that will execute in the context of other users' browsers when they view affected pages. The vulnerability falls under CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding. From an operational perspective this vulnerability poses significant risk to web applications as it allows attackers to steal session cookies, perform unauthorized actions on behalf of users, redirect victims to malicious sites, or deface web pages. The impact extends beyond simple data theft as it can enable more sophisticated attacks such as credential harvesting or privilege escalation within the application context. According to ATT&CK framework this vulnerability maps to T1059.007 for script execution and T1566 for phishing attacks through malicious web content. The vulnerability exists due to insufficient sanitization of user inputs in the administrative board configuration interface, where the application fails to properly escape special characters in HTML context. This allows attackers to inject script tags or event handlers that execute when the page loads, potentially compromising all users who access the affected board. The attack vector requires minimal privileges as the vulnerability exists in an administrative configuration endpoint that may be accessible to authenticated users with appropriate permissions. Mitigation strategies should include implementing proper input validation and output encoding for all user-supplied data, applying the latest security patches from the GNUBOARD5 maintainers, and configuring web application firewalls to detect and block suspicious script injection patterns. Additionally, organizations should conduct regular security assessments of their web applications to identify similar input validation flaws that could enable similar attack vectors. The vulnerability demonstrates the critical importance of proper sanitization of all user inputs in web applications and highlights the need for defense-in-depth approaches that combine multiple security controls to protect against persistent threats.