CVE-2020-23219 in Monstra
Summary
by MITRE • 07/02/2021
Monstra CMS 3.0.4 allows attackers to execute arbitrary code via a crafted payload entered into the "Snippet content" field under the "Edit Snippet" module.
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Analysis
by VulDB Data Team • 07/09/2021
The vulnerability identified as CVE-2020-23219 represents a critical remote code execution flaw within Monstra CMS version 3.0.4 that stems from inadequate input validation and sanitization mechanisms. This vulnerability specifically targets the "Snippet content" field within the "Edit Snippet" administrative module, creating a pathway for malicious actors to inject and execute arbitrary code on the affected system. The flaw demonstrates a classic lack of proper security controls in web application frameworks, where user-supplied data is not adequately filtered or escaped before being processed and stored within the application's database or execution environment.
The technical implementation of this vulnerability occurs through the improper handling of user input within the snippet editing functionality. When administrators or authorized users modify snippet content through the web interface, the application fails to validate or sanitize the input data, allowing attackers to craft malicious payloads that can be executed within the context of the web server. This weakness aligns with CWE-94, which describes inadequate input validation leading to code injection vulnerabilities, and represents a direct violation of secure coding practices that mandate proper sanitization of all user-provided data before it is processed or stored. The vulnerability can be exploited through various techniques including but not limited to php code injection, shell command execution, or other server-side code manipulation methods that leverage the lack of proper input filtering.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with complete control over the affected CMS instance and potentially the underlying server infrastructure. Successful exploitation can result in unauthorized data access, data modification or deletion, privilege escalation, and the establishment of persistent backdoors within the compromised environment. Attackers can leverage this vulnerability to gain shell access to the server, deploy malware, steal sensitive information, or use the compromised system as a launch point for further attacks against internal networks. The vulnerability affects the availability, integrity, and confidentiality of the web application, making it a critical concern for organizations relying on Monstra CMS for their content management needs.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation strategies to protect their systems. The most critical immediate action involves applying the vendor-provided security patches or updates that address the input validation flaw in the snippet handling module. Additionally, administrators should implement web application firewall rules to monitor and block suspicious payload patterns targeting the snippet editing functionality. Network segmentation and privilege separation should be enforced to limit the potential damage from successful exploitation attempts. The mitigation approach should also include comprehensive monitoring of administrative access logs and user activity within the snippet management module to detect anomalous behavior that may indicate exploitation attempts. Security teams should conduct thorough vulnerability assessments of their web applications and ensure that proper input validation and sanitization mechanisms are implemented across all user-facing interfaces to prevent similar vulnerabilities from occurring in other parts of the application stack. This vulnerability serves as a reminder of the importance of adhering to secure coding practices and maintaining up-to-date security controls as outlined in the ATT&CK framework's application security categories.