CVE-2018-17036 in UCMS
Summary
by MITRE
An issue was discovered in UCMS 1.4.6. It allows PHP code injection during installation via the systemdomain parameter to install/index.php, as demonstrated by injecting a phpinfo() call into /inc/config.php.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 03/23/2020
The vulnerability identified as CVE-2018-17036 represents a critical PHP code injection flaw within the UCMS 1.4.6 content management system. This security weakness occurs during the installation process when the systemdomain parameter in install/index.php fails to properly validate or sanitize user input. The vulnerability stems from insufficient input validation mechanisms that allow malicious actors to inject arbitrary PHP code directly into the system configuration files. The specific exploitation technique involves injecting a phpinfo() function call into the /inc/config.php file, which demonstrates the severity of the flaw as it enables attackers to execute arbitrary code within the context of the web application.
The technical implementation of this vulnerability aligns with CWE-94, which describes the improper execution of code due to insufficient input validation. Attackers can leverage this weakness by manipulating the systemdomain parameter during installation to inject malicious PHP code that gets executed and written to the configuration file. This creates a persistent backdoor within the application's configuration, allowing for continued unauthorized access and code execution. The vulnerability is particularly dangerous because it occurs during the installation phase when the system is typically less protected and when administrators may not be actively monitoring input validation processes. The injection targets the /inc/config.php file which serves as a critical configuration component, making the impact of successful exploitation substantial.
The operational impact of CVE-2018-17036 extends beyond simple code execution to encompass full system compromise and potential data breaches. Once exploited, attackers can gain persistent access to the web server, enabling them to escalate privileges, access sensitive data, modify content, or establish further footholds within the network infrastructure. The vulnerability creates a condition where the injected PHP code becomes part of the legitimate application behavior, making detection more difficult and allowing for long-term persistence. This type of vulnerability directly maps to ATT&CK technique T1059.007 for PHP, where adversaries use PHP code execution to maintain access and perform further malicious activities. The installation phase exploitation also aligns with ATT&CK technique T1078.004 for valid accounts, as successful exploitation can lead to unauthorized administrative access.
Mitigation strategies for CVE-2018-17036 require immediate patching of the UCMS 1.4.6 software to address the input validation flaw in the installation process. Organizations should implement strict input sanitization measures that validate and filter all user-supplied parameters before processing them in the installation script. The recommended approach includes implementing proper parameter validation using allowlists, escaping special characters, and employing secure coding practices that prevent code injection vulnerabilities. Additionally, network segmentation and access controls should be implemented to limit exposure during installation phases, while monitoring systems should be deployed to detect unusual file modifications in configuration directories. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other applications, with particular attention to input validation practices in installation and configuration processes. The vulnerability highlights the importance of following secure coding standards and implementing defense-in-depth strategies to protect against code injection attacks that can occur at any stage of application lifecycle including installation and setup phases.