CVE-2018-16287 in SuperSign CMS
Summary
by MITRE
LG SuperSign CMS allows file upload via signEzUI/playlist/edit/upload/..%2f URIs.
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Analysis
by VulDB Data Team • 03/24/2020
The vulnerability CVE-2018-16287 represents a critical file upload flaw in LG SuperSign CMS version 4.3.0 and earlier, which enables remote attackers to bypass authentication mechanisms and execute arbitrary file uploads through specifically crafted URI paths. This vulnerability exists within the signEzUI component of the CMS system, specifically in the playlist/edit/upload endpoint where the application fails to properly validate or sanitize input paths containing encoded forward slashes. The flaw allows attackers to traverse directory structures and upload malicious files to arbitrary locations on the server, potentially leading to complete system compromise.
This vulnerability falls under the CWE-434 category of Unrestricted Upload of File with Dangerous Type, which is classified as a critical weakness in software applications that accept file uploads without proper validation. The technical implementation of this flaw demonstrates a classic path traversal vulnerability combined with insecure file upload handling, where the application does not adequately sanitize the URI path parameter before processing file upload requests. The encoded forward slash sequence ..%2f in the URI allows attackers to manipulate the file upload destination path, effectively bypassing the intended directory restrictions and gaining access to sensitive system directories where critical files are stored.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, as it provides attackers with a potential foothold for more sophisticated attacks within the LG SuperSign CMS environment. Attackers could upload web shells, malicious scripts, or other exploit payloads that would allow them to execute arbitrary code on the server, potentially leading to full system compromise, data exfiltration, or disruption of digital signage services. The vulnerability affects organizations that rely on LG SuperSign CMS for managing digital signage networks, which often contain sensitive information and may be deployed in critical infrastructure environments where unauthorized access could have significant operational and security implications.
Organizations should immediately implement mitigations including patching to the latest version of LG SuperSign CMS where this vulnerability has been addressed, implementing proper input validation and sanitization for all URI paths, and restricting file upload functionality to authenticated users only. Network segmentation and monitoring should be enhanced to detect unusual file upload patterns, while access controls should be strengthened to limit administrative privileges. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, as it represents a common attack vector targeting web applications, and T1059 - Command and Scripting Interpreter, as successful exploitation would likely involve executing malicious code on the compromised system. Additionally, organizations should consider implementing web application firewalls and regular security assessments to identify similar vulnerabilities in their digital signage infrastructure and prevent exploitation of similar weaknesses in other components of their security ecosystem.