CVE-2018-17868 in H660GW
Summary
by MITRE
DASAN H660GW devices have Stored XSS in the Port Forwarding functionality.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 03/28/2020
The vulnerability CVE-2018-17868 represents a stored cross-site scripting flaw discovered in DASAN H660GW network devices, specifically within their port forwarding configuration functionality. This critical security weakness allows attackers to inject malicious scripts that persist on the device and execute when legitimate users access the affected web interface. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the device's web management interface, where user-supplied data is not properly escaped before being rendered back to users. The DASAN H660GW series devices are commonly deployed in residential and small office environments, making them attractive targets for cybercriminals seeking to establish persistent access points within networks. The stored nature of this XSS vulnerability means that malicious payloads remain embedded in the device's configuration until manually removed, creating a long-term threat vector that can be exploited by both external attackers and potentially compromised insiders.
The technical exploitation of this vulnerability occurs when an attacker submits malicious input through the port forwarding configuration parameters, which are then stored in the device's memory or configuration database. When administrators or other authorized users subsequently view or interact with the port forwarding settings through the web interface, the malicious scripts execute in the context of the victim's browser session. This allows attackers to potentially steal session cookies, perform unauthorized administrative actions, redirect users to malicious websites, or extract sensitive network information. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and demonstrates how insufficient input validation can create persistent security risks within web applications. The attack surface is particularly concerning given that many network administrators rely on web interfaces for routine configuration tasks, making legitimate users potential victims of these stored attacks. The vulnerability also maps to ATT&CK technique T1059.007, which covers scripting through web shells, as the malicious scripts can be used to establish persistent command and control capabilities.
The operational impact of CVE-2018-17868 extends beyond immediate script execution, as it provides attackers with a foothold for further network exploitation and reconnaissance activities. Once an attacker successfully injects malicious scripts, they can leverage the compromised device as a pivot point to conduct internal network scanning, access other network resources, or deploy additional malware. The persistent nature of stored XSS means that even after the initial compromise, the attack remains active until the device is properly patched or the configuration is manually cleared. Organizations using DASAN H660GW devices face significant risk of unauthorized access to their network infrastructure, potentially leading to data breaches, service disruption, or complete network compromise. The vulnerability affects not only the immediate device but can also impact the broader network security posture, as compromised devices often serve as entry points for more extensive attacks. Network security teams must consider this vulnerability as part of their overall risk assessment, particularly in environments where network device management interfaces are accessible from untrusted networks or where administrative access is not properly secured. The incident highlights the critical importance of implementing proper input validation and output encoding mechanisms in all web-facing applications, as well as the necessity of regular security assessments and prompt patch management for network infrastructure devices.