CVE-2018-9209 in php-traditional-server
Summary
by MITRE
Unauthenticated arbitrary file upload vulnerability in FineUploader php-traditional-server <= v1.2.2
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Analysis
by VulDB Data Team • 04/14/2020
The CVE-2018-9209 vulnerability represents a critical security flaw in the FineUploader php-traditional-server component affecting versions up to v1.2.2. This vulnerability enables unauthenticated attackers to upload arbitrary files to the target system, fundamentally compromising the server's integrity and potentially leading to full system compromise. The issue arises from insufficient input validation and access control mechanisms within the file upload functionality, creating a pathway for malicious actors to bypass authentication requirements and execute unauthorized operations.
The technical implementation of this vulnerability stems from the lack of proper file type validation and authentication checks in the php-traditional-server component. Attackers can exploit this weakness by sending specially crafted requests to the upload endpoint without requiring any valid credentials or session tokens. The system fails to properly validate the file extensions, content types, or file attributes, allowing attackers to upload malicious files such as php shells, web shells, or other executable content. This flaw directly maps to CWE-434 which describes the weakness of allowing untrusted data to be uploaded to a web server and executed.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with persistent access to the compromised system. Once an attacker successfully uploads malicious files, they can establish backdoors, escalate privileges, and potentially move laterally within the network. The vulnerability can be exploited through simple http requests, making it particularly dangerous as it requires no specialized tools or complex attack chains. This weakness enables attackers to gain unauthorized code execution, data exfiltration, and system persistence, all without the need for legitimate credentials or user interaction.
Security professionals should implement immediate mitigations including upgrading to versions of FineUploader that address this vulnerability, implementing strict file type validation, and enforcing proper authentication controls. Network segmentation and monitoring for unusual file upload activities should be deployed to detect potential exploitation attempts. The vulnerability aligns with several ATT&CK techniques including T1105 for ingress tool transfer and T1059 for command and scripting interpreter, highlighting the multi-stage nature of attacks that can leverage this weakness. Organizations should also consider implementing web application firewalls to detect and block malicious upload requests, while conducting regular security assessments to identify similar vulnerabilities in other components of their web applications.