CVE-2020-19786 in CSZ CMS
Summary
by MITRE • 03/23/2023
File upload vulnerability in CSKaza CSZ CMS v.1.2.2 fixed in v1.2.4 allows attacker to execute aritrary commands and code via crafted PHP file.
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Analysis
by VulDB Data Team • 04/13/2023
The CVE-2020-19786 vulnerability represents a critical file upload flaw in the CSKaza CSZ CMS version 1.2.2 that was subsequently patched in version 1.2.4. This vulnerability stems from inadequate input validation and sanitization mechanisms within the content management system's file upload functionality, creating a pathway for malicious actors to compromise affected systems. The flaw specifically allows attackers to upload malicious PHP files that can execute arbitrary commands and code on the target server, fundamentally undermining the security posture of any organization utilizing the vulnerable software.
The technical implementation of this vulnerability involves a lack of proper file type validation and content inspection within the CMS upload handler. Attackers can craft malicious PHP files with extensions that bypass initial filtering mechanisms, or exploit the system's inability to properly validate file contents against known malicious patterns. This weakness directly maps to CWE-434, which describes the vulnerability of applications accepting files from untrusted sources without proper validation. The vulnerability enables attackers to upload backdoor scripts or web shells that can be executed by the web server, providing persistent access to the compromised system. The flaw operates at the application layer and can be exploited through standard HTTP POST requests targeting the CMS file upload endpoint.
The operational impact of this vulnerability extends far beyond simple unauthorized file uploads, as it provides attackers with complete command execution capabilities on the affected server. Once a malicious PHP file is successfully uploaded and executed, attackers can perform a wide range of malicious activities including data exfiltration, privilege escalation, lateral movement within the network, and establishment of persistent backdoors. The vulnerability can be exploited through various attack vectors including web application penetration testing, automated scanning tools, or social engineering campaigns targeting administrators. Organizations may face significant security breaches, data loss, and compliance violations when systems running vulnerable versions of CSZ CMS are compromised, particularly in environments where the CMS handles sensitive user data or critical business functions.
Mitigation strategies for CVE-2020-19786 require immediate deployment of the patched version 1.2.4 and comprehensive security hardening of the CMS installation. System administrators should implement strict file type validation, enforce content-based file inspection, and restrict file upload permissions to authenticated users only. The implementation of web application firewalls and security monitoring solutions can help detect and prevent exploitation attempts. Organizations should also conduct thorough security audits of their CMS installations, remove any previously uploaded suspicious files, and implement proper access controls for file upload functionality. According to ATT&CK framework, this vulnerability maps to T1059.007 for command and script injection and T1505.003 for server-side includes, highlighting the need for layered security approaches that address both the immediate vulnerability and broader attack surface considerations. Regular security updates, vulnerability assessments, and security awareness training for administrators are essential components of a comprehensive defense strategy against such threats.