CVE-2019-17536 in Gila
Summary
by MITRE
Gila CMS through 1.11.4 allows Unrestricted Upload of a File with a Dangerous Type via the moveAction function in core/controllers/fm.php. The attacker needs to use admin/media_upload and fm/move.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2019-17536 represents a critical file upload restriction flaw within Gila CMS versions 1.11.4 and earlier. This weakness stems from insufficient validation mechanisms in the file management system, specifically within the moveAction function located in core/controllers/fm.php. The vulnerability allows authenticated attackers with administrative privileges to bypass file type restrictions and upload malicious files that could compromise the entire web application infrastructure. The attack vector requires the exploitation of two specific endpoints: admin/media_upload for initial file placement and fm/move for the actual file relocation process, creating a multi-step attack workflow that leverages legitimate administrative functions.
The technical implementation of this vulnerability falls under CWE-434, which describes unrestricted upload of files with dangerous types. The flaw occurs because the application fails to properly validate file extensions, MIME types, or file contents before allowing file operations to proceed. When administrators use the media_upload functionality followed by the moveAction function, the system does not adequately verify whether uploaded files contain potentially malicious content such as php scripts, executables, or other dangerous file formats. This oversight creates a pathway for attackers to execute arbitrary code on the server, potentially leading to complete system compromise.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with persistent access to the compromised system. Once an attacker successfully uploads a malicious file through this vulnerability, they can execute commands remotely, potentially gaining shell access to the web server. The implications include data theft, service disruption, lateral movement within the network, and potential establishment of backdoors for continued access. This vulnerability is particularly dangerous because it operates within the legitimate administrative interface, making malicious activity harder to detect through standard monitoring systems and potentially bypassing security controls that do not specifically target file upload validation.
Organizations using affected Gila CMS versions should immediately implement multiple layers of mitigation strategies. The primary remediation involves updating to the latest stable version of Gila CMS where this vulnerability has been patched. Additionally, administrators should implement strict file type validation at multiple points in the upload process, including server-side checks that verify file extensions, MIME types, and actual file content rather than relying solely on client-side validation. Network segmentation and access controls should be enforced to limit administrative privileges to only necessary personnel. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, with potential subsequent techniques including T1059 - Command and Scripting Interpreter and T1078 - Valid Accounts for maintaining persistence. Security monitoring should include detection of unusual file upload patterns and unauthorized access to administrative interfaces to identify potential exploitation attempts.