CVE-2016-9419 in MyBB
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the Admin control panel in MyBB (aka MyBulletinBoard) before 1.8.8 and MyBB Merge System before 1.8.8 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 08/08/2020
The CVE-2016-9419 vulnerability represents a critical cross-site scripting flaw discovered in MyBB forums and the MyBB Merge System prior to version 1.8.8. This vulnerability resides within the administrative control panel of the forum software, making it particularly dangerous as it could potentially allow attackers to execute malicious code in the context of administrator sessions. The vulnerability's impact extends beyond simple script injection, as it provides attackers with a potential pathway to gain elevated privileges and compromise entire forum installations.
The technical nature of this XSS vulnerability stems from insufficient input validation and output sanitization within the administrative interface. Attackers can exploit this weakness by crafting malicious payloads that get executed when administrators view affected pages or interact with the control panel. The unspecified vectors suggest that multiple entry points within the admin interface could be compromised, potentially including form fields, URL parameters, or administrative configuration settings. This broad attack surface increases the likelihood of successful exploitation and makes the vulnerability particularly challenging to defend against completely.
The operational impact of this vulnerability is severe for organizations relying on MyBB forums for community engagement or business operations. An attacker who successfully exploits this vulnerability could gain access to administrative functions, potentially leading to complete forum compromise. This includes the ability to modify forum content, delete posts, manipulate user permissions, or even install backdoors. The vulnerability also poses risks to user data integrity and privacy, as administrators often have access to sensitive user information. Furthermore, the compromised forum could serve as a platform for distributing malware to other users or for conducting further attacks against the organization's network infrastructure.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications. The attack pattern follows typical XSS exploitation techniques documented in the MITRE ATT&CK framework under the T1059.007 technique for command and scripting interpreter, as attackers can execute malicious scripts in the context of legitimate users. Organizations should implement multiple layers of defense including input validation, output encoding, and regular security updates to mitigate such risks. The vulnerability also highlights the importance of secure coding practices and the need for regular security assessments of administrative interfaces, which are often overlooked in favor of frontend security measures.
The remediation strategy for this vulnerability involves immediate deployment of patches or updates to MyBB version 1.8.8 or later, which contain proper input validation and output sanitization measures. Organizations should also implement additional security controls such as web application firewalls, content security policies, and regular security audits of administrative interfaces. Given that this vulnerability affects the control panel, it is crucial to ensure that administrative access is properly secured with multi-factor authentication and that access logs are monitored for suspicious activities. Regular security training for administrators about recognizing potential XSS attack vectors can also significantly reduce the risk of successful exploitation.