CVE-2016-6195 in vBulletin
Summary
by MITRE
SQL injection vulnerability in forumrunner/includes/moderation.php in vBulletin before 4.2.2 Patch Level 5 and 4.2.3 before Patch Level 1 allows remote attackers to execute arbitrary SQL commands via the postids parameter to forumrunner/request.php, as exploited in the wild in July 2016.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/02/2025
The vulnerability identified as CVE-2016-6195 represents a critical SQL injection flaw within the vBulletin forum software ecosystem, specifically affecting versions prior to 4.2.2 Patch Level 5 and 4.2.3 Patch Level 1. This vulnerability resides in the forumrunner module, which serves as a mobile application interface for vBulletin forums, making it particularly dangerous as it targets mobile users who may be less vigilant about security. The flaw manifests through the postids parameter in the forumrunner/request.php endpoint, creating an attack vector that enables remote code execution through maliciously crafted SQL commands. The vulnerability was actively exploited in the wild during July 2016, demonstrating its real-world impact and the urgency with which organizations needed to address it. This type of vulnerability falls under CWE-89, which specifically addresses SQL injection weaknesses in software applications, representing one of the most prevalent and dangerous categories of web application vulnerabilities. The attack surface is particularly concerning as it leverages the forumrunner module, which provides mobile access to forum content, potentially allowing attackers to compromise entire forum installations and access sensitive user data.
The technical implementation of this vulnerability stems from improper input validation and sanitization within the moderation.php script that processes user-supplied data. When the postids parameter is passed to forumrunner/request.php, the application fails to properly escape or validate the input before incorporating it into SQL queries. This allows attackers to inject malicious SQL syntax that can manipulate the database structure, extract sensitive information, or even execute administrative commands on the underlying database system. The exploitation process typically involves crafting a specially formatted postids parameter that bypasses normal input filtering mechanisms, enabling the attacker to inject arbitrary SQL commands that are then executed by the database engine. This vulnerability specifically targets the mobile interface functionality of vBulletin, making it particularly insidious as it can be exploited through mobile applications that users may not expect to be vulnerable to such attacks, potentially leading to widespread compromise of user accounts and forum data integrity. The vulnerability's exploitation demonstrates the critical importance of input validation in web applications and the severe consequences that can arise from inadequate sanitization of user-supplied data.
The operational impact of CVE-2016-6195 extends far beyond simple data theft, as successful exploitation can result in complete compromise of forum installations and potential lateral movement within network environments. Attackers can leverage this vulnerability to access user credentials, personal information, private messages, and forum content, potentially leading to identity theft, reputation damage, and regulatory compliance violations. The vulnerability's presence in mobile interfaces also means that attackers can compromise mobile users who may be accessing forums from less secure network environments such as public Wi-Fi networks or personal devices. Organizations using affected vBulletin versions face significant risks including data breaches, service disruption, and potential legal consequences under various data protection regulations. The vulnerability's exploitation in July 2016 indicates that it was actively weaponized in the wild, meaning that organizations were not merely at theoretical risk but faced actual, ongoing threats from malicious actors. This particular vulnerability aligns with ATT&CK technique T1071.004 for application layer protocol usage and T1190 for exploit public-facing application, demonstrating how attackers can leverage web application vulnerabilities to establish persistent access to target systems. The impact on user trust and forum integrity can be devastating, potentially leading to complete loss of community engagement and reputational damage for organizations running affected software.
Mitigation strategies for CVE-2016-6195 require immediate implementation of the official patches released by vBulletin, specifically upgrading to versions 4.2.2 Patch Level 5 or 4.2.3 Patch Level 1, which contain the necessary fixes for the SQL injection vulnerability. Organizations should implement proper input validation and parameterized queries throughout their applications to prevent similar vulnerabilities from occurring in the future, as this represents a fundamental security principle that should be applied to all database interactions. Network monitoring should be enhanced to detect unusual patterns in forum access and database query activity that might indicate exploitation attempts. Security teams should conduct comprehensive vulnerability assessments of all web applications to identify similar input validation issues that could be exploited in the same manner. The implementation of web application firewalls and intrusion detection systems can provide additional layers of protection against exploitation attempts. Organizations should also review their incident response procedures to ensure they are prepared to handle potential exploitation of this vulnerability, including forensic analysis capabilities and communication protocols for affected users. Regular security updates and patch management processes should be strengthened to prevent similar vulnerabilities from remaining unaddressed for extended periods. The vulnerability serves as a critical reminder of the importance of maintaining up-to-date security patches and the potential consequences of delaying critical security updates in web application environments.