CVE-2019-16066 in Enigma NMS
Summary
by MITRE
An unrestricted file upload vulnerability exists in user and system file upload functions in NETSAS Enigma NMS 65.0.0 and prior. This allows an attacker to upload malicious files and perform arbitrary code execution on the system.
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Analysis
by VulDB Data Team • 04/18/2024
The vulnerability identified as CVE-2019-16066 represents a critical unrestricted file upload flaw within the NETSAS Enigma Network Management System version 65.0.0 and earlier releases. This weakness resides in both user and system file upload functionalities, creating a significant security exposure that can be exploited by malicious actors to gain unauthorized access and execute arbitrary code on the affected system. The vulnerability stems from insufficient validation and sanitization of file uploads, allowing attackers to bypass security controls that should prevent the execution of potentially harmful file types.
The technical implementation of this flaw involves the absence of proper input validation mechanisms within the file upload handlers. When users or system processes attempt to upload files through the application interface, the system fails to adequately verify file extensions, MIME types, or file contents against a whitelist of allowed formats. This omission creates a pathway for attackers to upload malicious files such as web shells, executable binaries, or scripts that can be executed within the context of the target system. The vulnerability aligns with CWE-434 Unrestricted Upload of File with Dangerous Type, which specifically addresses the risks associated with accepting files without proper validation. Attackers can leverage this weakness to upload files that will be processed and executed by the web server, potentially leading to complete system compromise.
The operational impact of CVE-2019-16066 extends beyond simple privilege escalation, as it provides attackers with persistent access to the network management system. Once an attacker successfully uploads a malicious file, they can execute arbitrary commands on the target system, potentially leading to data exfiltration, lateral movement within the network, or establishment of backdoors for continued access. The severity of this vulnerability is compounded by the fact that it affects both user and system upload functions, meaning that even legitimate administrative operations could be compromised. From an attack perspective, this vulnerability maps to multiple ATT&CK techniques including T1190 Exploit Public-Facing Application, T1059 Command and Scripting Interpreter, and T1078 Valid Accounts, as attackers can leverage this flaw to establish persistent access and execute malicious payloads. The attack surface is particularly concerning given that network management systems typically contain sensitive configuration data and serve as central points of control for network infrastructure.
Mitigation strategies for CVE-2019-16066 require immediate implementation of multiple defensive measures to address the root cause of the vulnerability. Organizations should implement strict file type validation mechanisms that enforce whitelisting of acceptable file extensions and MIME types, ensuring that only known safe file formats can be uploaded to the system. The implementation of proper file content verification through file signature checks and MIME type detection helps prevent attackers from disguising malicious files with legitimate extensions. Additionally, upload directories should be configured with restricted permissions and should not be executable, preventing uploaded files from being directly executed by the web server. Network segmentation and application firewalls can provide additional layers of protection by limiting access to upload functions and monitoring for suspicious file upload activities. Regular security updates and patches should be applied immediately upon availability, as NETSAS has likely released fixes for this vulnerability. The implementation of automated file scanning solutions that can detect and quarantine potentially malicious uploads adds another protective layer to the defense-in-depth strategy. Organizations should also conduct regular security assessments of their network management systems to identify and remediate similar vulnerabilities that could provide attackers with similar pathways to system compromise.