CVE-2015-7808 in vBulletin
Summary
by MITRE
The vB_Api_Hook::decodeArguments method in vBulletin 5 Connect 5.1.2 through 5.1.9 allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via a crafted serialized object in the arguments parameter to ajax/api/hook/decodeArguments.
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Analysis
by VulDB Data Team • 11/12/2024
The vulnerability identified as CVE-2015-7808 represents a critical security flaw in vBulletin 5 Connect versions 5.1.2 through 5.1.9 that enables remote attackers to perform PHP object injection attacks. This vulnerability exists within the vB_Api_Hook::decodeArguments method, which processes incoming API requests through the ajax/api/hook/decodeArguments endpoint. The flaw occurs when the application fails to properly validate or sanitize serialized object data passed in the arguments parameter, creating a pathway for malicious actors to inject crafted PHP objects that can be unserialized and executed on the target server.
The technical implementation of this vulnerability falls under CWE-502, which specifically addresses "Deserialization of Untrusted Data" in software systems. When an attacker sends a specially crafted serialized PHP object through the arguments parameter, the vulnerable application's decodeArguments method attempts to unserialize this data without adequate input validation or sanitization. This deserialization process can trigger the execution of arbitrary PHP code, allowing attackers to perform a wide range of malicious activities including remote code execution, data exfiltration, and system compromise. The attack vector is particularly dangerous because it operates over the network without requiring authentication, making it accessible to any remote user who can submit requests to the affected API endpoint.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with complete control over the affected vBulletin installation. Successful exploitation can lead to full system compromise, enabling attackers to execute commands with the privileges of the web server process, access sensitive user data, modify content, or establish persistent backdoors. The vulnerability affects organizations using vBulletin 5 Connect versions in the specified range, potentially exposing thousands of websites that rely on this forum software to unauthorized access and control. The attack surface is broad since many organizations use vBulletin for community forums, support systems, and knowledge bases, making this vulnerability particularly dangerous in enterprise environments where such platforms may contain sensitive information.
Mitigation strategies for CVE-2015-7808 should focus on immediate patching of the vulnerable vBulletin versions, with administrators upgrading to versions 5.1.10 or later where this vulnerability has been addressed. Organizations should also implement network-level protections such as web application firewalls that can detect and block malicious serialized object data patterns in API requests. Input validation and sanitization measures should be strengthened to ensure that all data passed to the decodeArguments method is properly validated before any deserialization occurs. Additionally, system administrators should consider implementing least privilege principles for web server processes, limiting the potential damage from successful exploitation, and establishing monitoring mechanisms to detect unusual API activity patterns that may indicate exploitation attempts. The vulnerability's classification under the ATT&CK framework would place it in the execution category, specifically targeting remote code execution capabilities that allow attackers to run arbitrary code on compromised systems.