CVE-2016-10756 in Kliqqi
Summary
by MITRE
Kliqqi 3.0.0.5 allows CSRF with resultant Arbitrary File Upload because module.php?module=upload can be used to configure the uploading of .php files, and then modules/upload/upload_main.php can be used for the upload itself.
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Analysis
by VulDB Data Team • 09/24/2023
The vulnerability identified as CVE-2016-10756 affects Kliqqi version 3.0.0.5, a content management system that suffers from a critical cross-site request forgery flaw combined with arbitrary file upload capabilities. This vulnerability stems from insufficient input validation and access control mechanisms within the application's file upload functionality. The issue arises from the design of the module.php script which allows configuration of file upload parameters through the module=upload parameter, creating an attack vector that can be exploited by malicious actors to gain unauthorized access to the system.
The technical flaw manifests through a two-stage process that bypasses normal security controls. First, an attacker can manipulate the module.php endpoint with the upload module parameter to configure the upload environment, effectively setting up the conditions for file uploads. Then, the attacker utilizes modules/upload/upload_main.php to execute the actual file upload operation, which can include malicious php files due to inadequate validation of file extensions and content. This vulnerability is classified under CWE-352, Cross-Site Request Forgery, and CWE-434, Unrestricted Upload of File with Dangerous Type, as it combines both authentication bypass and insecure file handling mechanisms.
The operational impact of this vulnerability is severe and multifaceted, as it enables remote code execution capabilities for attackers who can upload malicious PHP scripts to the target server. Once successful, an attacker can execute arbitrary code on the web server, potentially leading to complete system compromise, data exfiltration, and persistent access to the compromised environment. The vulnerability affects not only the immediate application but also poses risks to the entire underlying infrastructure, as the uploaded PHP files can be leveraged to establish backdoors, perform lateral movement, or conduct further attacks within the network. This type of vulnerability is particularly dangerous because it can be exploited through social engineering techniques where users are tricked into visiting malicious websites that automatically submit CSRF requests to the vulnerable Kliqqi installation.
Security professionals should implement multiple layers of mitigation strategies to address this vulnerability. The primary recommendation involves implementing proper CSRF protection mechanisms including anti-CSRF tokens that are generated per user session and validated on each request. Additionally, strict file type validation must be enforced on the server-side, rejecting any file with php extensions or executable content regardless of the upload configuration. The application should also implement proper access controls and authentication checks to ensure that only authorized users can access the upload functionality. According to ATT&CK framework, this vulnerability maps to T1059.007 for Command and Scripting Interpreter: Python and T1078.004 for Valid Accounts: Default Accounts, as it can be used to establish persistent access and execute malicious code. Organizations should also consider implementing web application firewalls, input sanitization, and regular security audits to prevent exploitation of similar vulnerabilities in the future. The remediation process requires immediate patching of the affected application version and implementation of proper security controls to prevent unauthorized file uploads and CSRF attacks, as the vulnerability can be exploited without authentication and can lead to complete system compromise.