CVE-2018-11241 in T-Router
Summary
by MITRE
An issue was discovered on SoftCase T-Router build 20112017 devices. A remote attacker can read and write to arbitrary files on the system as root, as demonstrated by code execution after writing to a crontab file. This is fixed in production builds as of Spring 2018.
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Analysis
by VulDB Data Team • 03/26/2020
The vulnerability CVE-2018-11241 represents a critical privilege escalation flaw affecting SoftCase T-Router devices running build 20112017. This issue stems from inadequate input validation and access control mechanisms within the router's web management interface, allowing remote attackers to bypass authentication and execute arbitrary commands with root privileges. The vulnerability exists in the device's file system access controls, where improper validation of user inputs enables attackers to manipulate system files directly through the web interface. This weakness is particularly dangerous as it operates at the system level, granting full administrative control over the device's operations and potentially exposing the entire network infrastructure to further compromise.
The technical exploitation of this vulnerability occurs through a combination of path traversal and command injection techniques that leverage the router's web application to access sensitive system files. Attackers can manipulate file paths to read and write to critical system components including configuration files, executable binaries, and scheduled task mechanisms such as crontab files. The specific exploitation vector demonstrates that remote attackers can write malicious code to crontab entries, which then executes automatically with root privileges, creating a persistent backdoor within the device. This represents a classic case of inadequate input sanitization and privilege separation, where the web interface fails to properly validate file access requests and enforce proper access controls. The vulnerability aligns with CWE-22 Path Traversal and CWE-78 Command Injection, both of which are fundamental security weaknesses that enable unauthorized system access and code execution.
The operational impact of CVE-2018-11241 extends far beyond the immediate compromise of individual devices, as it provides attackers with complete control over network infrastructure and potentially enables lateral movement within connected networks. Once an attacker gains root access through this vulnerability, they can modify network configurations, redirect traffic, install malware, or use the compromised device as a pivot point for attacking other systems within the network. The persistent nature of the exploitation through crontab modifications means that even if the initial attack vector is patched, the attacker maintains long-term access to the device. This vulnerability particularly affects enterprise and industrial network environments where routers serve as critical network infrastructure components, potentially allowing attackers to disrupt services, steal sensitive data, or establish command and control channels. The timing of the vulnerability disclosure in 2018 indicates that it remained unpatched for several months, providing attackers with ample opportunity to exploit the weakness in production environments.
Mitigation strategies for CVE-2018-11241 require immediate remediation through firmware updates that address the underlying input validation and access control flaws. Organizations should implement network segmentation to isolate affected devices and monitor for suspicious network activity that may indicate exploitation attempts. The recommended approach includes disabling unnecessary web management interfaces, implementing strict firewall rules, and conducting thorough network scans to identify potentially compromised devices. Security measures should also include regular firmware updates, proper access control configuration, and monitoring of system logs for unauthorized file modifications. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and persistence, specifically T1068 Local Privilege Escalation and T1059 Command and Scripting Interpreter. Organizations should also consider implementing network monitoring solutions that can detect anomalous file access patterns and automated task scheduling modifications that may indicate exploitation attempts. The vulnerability highlights the importance of secure coding practices and proper input validation in network device firmware development, emphasizing the need for comprehensive security testing and vulnerability assessments before deployment in production environments.