CVE-2018-18672 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 "board head contents" parameter, aka the adm/board_form_update.php bo_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 board head contents parameter. This vulnerability specifically affects the adm/board_form_update.php endpoint where the bo_content_head parameter is processed without adequate input validation or output sanitization. The flaw represents a classic reflected cross-site scripting vulnerability where user-supplied data is directly incorporated into web page responses without proper encoding or filtering mechanisms.
The technical implementation of this vulnerability stems from insufficient sanitization of the bo_content_head parameter within the administrative board form update functionality. When administrators configure board settings or modify content headers, the system accepts input that is not properly escaped or validated before being rendered in web pages. This creates an opportunity for attackers to craft malicious payloads that execute in the context of other users' browsers who visit affected pages. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications, and aligns with ATT&CK technique T1566.001 for initial access through malicious web content.
The operational impact of this vulnerability is significant as it allows attackers to execute arbitrary code in the browsers of authenticated users who visit affected board pages. Attackers could potentially steal session cookies, perform unauthorized actions on behalf of users, redirect victims to malicious sites, or deface the affected boards. Given that this affects the administrative configuration interface, successful exploitation could lead to complete compromise of board settings and potentially broader system access if the application lacks proper access controls. The vulnerability is particularly dangerous in environments where administrators regularly update board content, as the attack surface expands with each configuration change.
Mitigation strategies should focus on implementing comprehensive input validation and output encoding for all user-supplied data within the bo_content_head parameter. The system should employ strict sanitization routines that remove or escape potentially dangerous characters and HTML tags before rendering content. Additionally, implementing proper content security policies and using secure coding practices such as parameterized queries and proper HTML escaping can prevent this class of vulnerability. Regular security audits of web applications should include thorough testing of all input parameters, particularly those used in administrative interfaces. The vulnerability also highlights the importance of following secure development practices as outlined in OWASP Top Ten and NIST cybersecurity guidelines for preventing injection flaws in web applications.