CVE-2018-8966 in zzcms
Summary
by MITRE
An issue was discovered in zzcms 8.2. It allows PHP code injection via the siteurl parameter to install/index.php, as demonstrated by injecting a phpinfo() call into /inc/config.php.
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Analysis
by VulDB Data Team • 01/16/2020
The vulnerability identified as CVE-2018-8966 represents a critical PHP code injection flaw within zzcms version 8.2, specifically affecting the installation process. This issue stems from inadequate input validation and sanitization mechanisms that fail to properly filter user-supplied data before incorporating it into the application's configuration files. The vulnerability manifests through the siteurl parameter in the install/index.php script, which directly influences how the application generates its configuration file at /inc/config.php. This allows an attacker to inject arbitrary PHP code into the system, potentially enabling full remote code execution capabilities.
The technical exploitation of this vulnerability follows a well-established pattern of insecure input handling that aligns with CWE-94, which describes the weakness of allowing code injection attacks. When an attacker supplies malicious input through the siteurl parameter, the application fails to validate or sanitize the data before writing it to the configuration file. This creates an environment where PHP code can be directly embedded into the system's operational files, enabling attackers to execute arbitrary commands on the server. The specific demonstration using phpinfo() shows that the vulnerability can be leveraged to extract system information, but the potential for more destructive payloads exists.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it fundamentally compromises the integrity and security posture of the entire zzcms installation. An attacker who successfully exploits this vulnerability gains the ability to execute arbitrary PHP code on the target system, potentially leading to complete system compromise. The vulnerability affects the installation phase of the application, meaning that any user with access to the installation interface can exploit this weakness, regardless of their authentication status. This makes the attack surface particularly broad and increases the likelihood of successful exploitation in environments where installation interfaces remain accessible to unauthorized users.
The security implications of CVE-2018-8966 align with several ATT&CK framework techniques, particularly those related to command and control operations and privilege escalation. The vulnerability enables adversaries to establish persistent access through code injection, potentially allowing them to deploy backdoors or establish reverse shells. Organizations using zzcms 8.2 should immediately implement mitigations including input validation, parameter sanitization, and access controls to prevent unauthorized users from reaching the installation interface. Additionally, the vulnerability demonstrates the importance of proper secure coding practices and input validation, as outlined in OWASP Top Ten and NIST cybersecurity guidelines. The recommended remediation involves patching the application to version 8.3 or later, implementing proper input validation mechanisms, and ensuring that installation interfaces are not accessible to untrusted users. Organizations should also consider network segmentation and monitoring to detect potential exploitation attempts and maintain proper system integrity through regular security assessments and vulnerability scanning procedures.