CVE-2020-17452 in flatCore
Summary
by MITRE
flatCore before 1.5.7 allows upload and execution of a .php file by an admin.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/10/2020
The vulnerability CVE-2020-17452 represents a critical security flaw in flatCore versions prior to 1.5.7 that enables administrative users to upload and execute arbitrary php files on the target system. This represents a severe privilege escalation vulnerability that directly compromises the integrity and confidentiality of the affected web application. The flaw exists within the file upload functionality of the content management system, where proper input validation and access controls are insufficiently implemented. According to CWE-434, this vulnerability falls under the category of Unrestricted Upload of File with Dangerous Type, which is a well-documented weakness that allows attackers to upload malicious files that can execute code on the server. The vulnerability is particularly concerning because it requires only administrative privileges to exploit, meaning that an attacker who has gained access to an admin account can immediately leverage this flaw to establish persistent access to the underlying server infrastructure.
The technical implementation of this vulnerability stems from inadequate sanitization of file upload parameters within the flatCore application's administrative interface. When an administrator uploads a file, the system fails to properly validate the file extension, content type, or file content, allowing malicious php files to bypass security checks. This flaw creates an execution path where uploaded php files can be directly executed by the web server, enabling attackers to run arbitrary code with the privileges of the web server process. The vulnerability is classified under the ATT&CK technique T1505.003 for Server Software Component, specifically focusing on the execution of malicious code through compromised administrative interfaces. The exploitation process typically involves uploading a php shell or webshell that can be subsequently accessed through the web server, providing attackers with remote command execution capabilities and potentially full system compromise.
The operational impact of CVE-2020-17452 extends far beyond simple code execution, as it fundamentally undermines the security model of the flatCore application and the systems it protects. Once exploited, attackers can perform various malicious activities including data exfiltration, privilege escalation, lateral movement within the network, and establishment of persistent backdoors. The vulnerability creates a persistent threat vector that can be exploited repeatedly, as the uploaded php files remain on the server until manually removed. Organizations running affected versions of flatCore face significant risk of data breaches, system compromise, and potential regulatory violations. The vulnerability affects not only the immediate web application but also the underlying infrastructure, as the executed code can potentially access database credentials, configuration files, and other sensitive system information. This type of vulnerability is particularly dangerous in environments where flatCore is used for content management, as it can lead to complete compromise of the web application and associated data assets.
Mitigation strategies for CVE-2020-17452 focus primarily on immediate patching and implementation of additional security controls. The most effective solution is upgrading to flatCore version 1.5.7 or later, which includes proper file validation and access control mechanisms. Organizations should also implement strict file upload restrictions including whitelisting of allowed file extensions, mandatory file type checking, and implementation of secure file storage practices. Additional protective measures include disabling unnecessary administrative functions, implementing multi-factor authentication for admin accounts, and conducting regular security audits of uploaded files. Network-based mitigations such as web application firewalls and intrusion detection systems can help detect and prevent exploitation attempts. The vulnerability demonstrates the importance of proper input validation and access control mechanisms as outlined in security frameworks like the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should also implement monitoring solutions to detect unauthorized file uploads and execution activities, as well as establish incident response procedures specifically designed to address code execution vulnerabilities. Regular security assessments and vulnerability scanning should be conducted to identify similar flaws in other applications and systems within the organization's infrastructure.