CVE-2016-6483 in vBulletin
Summary
by MITRE
The media-file upload feature in vBulletin before 3.8.7 Patch Level 6, 3.8.8 before Patch Level 2, 3.8.9 before Patch Level 1, 4.x before 4.2.2 Patch Level 6, 4.2.3 before Patch Level 2, 5.x before 5.2.0 Patch Level 3, 5.2.1 before Patch Level 1, and 5.2.2 before Patch Level 1 allows remote attackers to conduct SSRF attacks via a crafted URL that results in a Redirection HTTP status code.
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Analysis
by VulDB Data Team • 09/24/2024
The vulnerability identified as CVE-2016-6483 represents a critical server-side request forgery flaw within the vBulletin forum software ecosystem. This weakness exists in multiple version ranges spanning vBulletin 3.x through 5.x, specifically affecting installations before the respective patch levels that were released to address this security concern. The vulnerability manifests through the media file upload functionality, which is a commonly used feature in online forums and community platforms where users can embed multimedia content from external sources. The flaw enables remote attackers to manipulate the system's behavior by crafting malicious URLs that trigger HTTP redirection responses, thereby bypassing normal security restrictions and potentially accessing internal network resources that should remain protected.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the media upload processing pipeline. When users attempt to upload media files by providing URLs, the system fails to properly validate or sanitize the provided URLs, allowing attackers to craft malicious inputs that contain redirection headers. This weakness aligns with CWE-918, which describes server-side request forgery vulnerabilities where applications fail to properly validate the target of requests made to external services. The vulnerability operates at the application layer and can be exploited through HTTP response manipulation, making it particularly dangerous in environments where internal network resources are accessible from the web server hosting the vulnerable forum software.
The operational impact of this vulnerability extends beyond simple data exfiltration or service disruption. Attackers can leverage this flaw to access internal systems that are typically isolated from external networks, potentially leading to lateral movement within the organization's infrastructure. This includes accessing internal web services, databases, or other systems that may contain sensitive information or critical business data. The vulnerability can also be used to conduct further reconnaissance activities, such as probing internal network boundaries or testing the security posture of the organization's internal infrastructure. Additionally, the attack can be automated and executed at scale, making it particularly dangerous for large organizations that host multiple vBulletin installations or have extensive user communities.
Organizations affected by this vulnerability should immediately implement comprehensive mitigation strategies that include applying the relevant security patches released by vBulletin to address the specific version ranges mentioned in the CVE description. Network-level protections such as web application firewalls should be configured to monitor and block suspicious URL patterns that may indicate attempts to exploit this vulnerability. Input validation controls should be strengthened to ensure that all URL parameters are properly sanitized and validated before being processed by the media upload functionality. Security monitoring should be enhanced to detect unusual traffic patterns or attempts to access internal resources through the forum's media upload feature. The vulnerability also highlights the importance of maintaining current security practices including regular security assessments, proper access controls, and network segmentation to limit the potential impact of similar vulnerabilities in the future. This issue demonstrates the critical need for organizations to maintain up-to-date security measures and proper input validation controls across all application components to prevent exploitation of similar server-side request forgery vulnerabilities.