CVE-2018-18669 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 title contents" parameter, aka the adm/board_form_update.php bo_subject parameter.
Be aware that VulDB is the high quality source for vulnerability data.
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 execute arbitrary web scripts or HTML code through the board title contents parameter. This vulnerability specifically affects the adm/board_form_update.php endpoint where the bo_subject parameter is processed without adequate input validation or output sanitization. The flaw represents a classic stored cross-site scripting vulnerability where malicious input is persisted in the application's database and subsequently rendered to other users without proper escaping or encoding. The vulnerability stems from insufficient sanitization of user-supplied data before it is stored and displayed within the web application interface. Attackers can exploit this weakness by crafting malicious payloads in the board title field that when rendered to other users will execute unintended JavaScript code within their browser context. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws and aligns with ATT&CK technique T1566.001 for initial access through spearphishing attachments or links. The impact of this vulnerability extends beyond simple script execution as it can enable session hijacking, credential theft, or redirection to malicious sites. The vulnerability is particularly concerning because it affects administrative functions where privileged users might interact with the compromised content. The lack of proper input validation and output encoding creates a persistent threat vector that can be exploited by attackers who gain access to the application's administrative interface or who can convince users to interact with the malicious content. This vulnerability demonstrates poor security practices in data handling and reinforces the importance of implementing comprehensive input validation and output encoding mechanisms. The attack surface is expanded due to the administrative nature of the affected endpoint, potentially allowing attackers to escalate privileges or gain deeper access to the system. Organizations using GNUBOARD5 should immediately implement proper sanitization of all user inputs and ensure that all output is properly encoded before being rendered to users. The vulnerability highlights the critical need for secure coding practices and regular security assessments to identify and remediate similar flaws in web applications. Implementing Content Security Policy headers and using frameworks with built-in protection against XSS attacks would significantly reduce the risk of exploitation. This vulnerability also emphasizes the importance of least privilege principles and proper access controls to limit the potential damage from compromised administrative functions.
The technical exploitation of this vulnerability requires minimal prerequisites as attackers only need to submit malicious content through the board title parameter. The persistence of the XSS vulnerability means that once the malicious payload is stored in the database, it will continue to affect users who view the affected board titles. This makes the vulnerability particularly dangerous for public-facing web applications where multiple users interact with the content. The vulnerability's impact is further amplified by the fact that it affects administrative functions which may contain sensitive information or provide access to critical system features. Security professionals should consider this vulnerability as part of broader web application security assessments and implement proper monitoring for suspicious input patterns. The vulnerability also serves as a reminder of the importance of regular security updates and patch management processes to prevent exploitation of known vulnerabilities. Organizations should establish secure coding guidelines that specifically address XSS prevention and ensure that all input validation and output encoding mechanisms are properly implemented. The combination of this vulnerability with other potential flaws in the application architecture could provide attackers with a foothold for more extensive compromise of the system.