CVE-2017-17976 in Perfex
Summary
by MITRE
In Utilities.php in Perfex CRM 1.9.7, Unrestricted file upload can lead to remote code execution.
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Analysis
by VulDB Data Team • 10/10/2025
The vulnerability identified as CVE-2017-17976 resides within the Utilities.php file of Perfex CRM version 1.9.7, representing a critical security flaw that enables attackers to upload arbitrary files to the target system. This issue stems from insufficient input validation and sanitization mechanisms within the file upload functionality, allowing malicious actors to bypass security controls and potentially execute arbitrary code on the affected server. The vulnerability manifests due to the application's failure to properly validate file extensions, MIME types, or file contents before processing uploads, creating a pathway for attackers to deploy malicious payloads.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-434, which specifically addresses the issue of unrestricted file upload. Attackers can leverage this flaw by crafting malicious files with extensions such as .php, .asp, or .jsp that are designed to execute commands on the server when accessed through the web application. The vulnerability's impact extends beyond simple file upload capabilities as it provides a potential foothold for attackers to establish persistent access, escalate privileges, and move laterally within the network infrastructure. This flaw particularly affects web applications that do not implement proper file type restrictions or content validation mechanisms, making it a common target for automated exploitation tools.
From an operational perspective, the consequences of this vulnerability can be devastating for organizations using Perfex CRM, as remote code execution capabilities allow attackers to compromise entire server environments. The attack surface is particularly concerning because CRM systems often contain sensitive customer data, financial information, and business-critical data that can be exfiltrated or manipulated. This vulnerability can be exploited through various attack vectors including web application penetration testing, automated scanning tools, or social engineering campaigns targeting system administrators. The ATT&CK framework categorizes this as a technique involving "T1190 - Exploit Public-Facing Application" and "T1059 - Command and Scripting Interpreter" where attackers can execute commands through the compromised upload functionality.
The mitigation strategies for CVE-2017-17976 should focus on implementing comprehensive file validation controls that adhere to industry best practices and security standards. Organizations must enforce strict file type validation by maintaining whitelists of allowed extensions and MIME types rather than relying on blacklists that can be easily bypassed. The implementation of proper content validation through file signature checks and MIME type verification provides additional layers of defense against malicious file uploads. Security patches should be applied immediately to update to newer versions of Perfex CRM that address this vulnerability, while network segmentation and access controls should be implemented to limit the potential impact of successful exploitation. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other applications and ensure that file upload functionalities are properly secured against unauthorized access and execution.