CVE-2023-31740 in E2000
Summary
by MITRE • 05/23/2023
There is a command injection vulnerability in the Linksys E2000 router with firmware version 1.0.06. If an attacker gains web management privileges, they can inject commands into the post request parameters WL_atten_bb, WL_atten_radio, and WL_atten_ctl in the apply.cgi interface, thereby gaining shell privileges.
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Analysis
by VulDB Data Team • 07/09/2026
The CVE-2023-31740 vulnerability represents a critical command injection flaw within the Linksys E2000 router firmware version 1.0.06, demonstrating a fundamental failure in input validation and sanitization within the router's web management interface. This vulnerability resides in the apply.cgi interface where specific parameter names WL_atten_bb, WL_atten_radio, and WL_atten_ctl are susceptible to malicious command injection attacks. The flaw stems from improper handling of user-supplied data within these parameters, allowing an attacker who has already gained web management access to execute arbitrary shell commands on the affected device. This represents a severe security weakness that transforms a legitimate administrative interface into a potential attack vector for privilege escalation and remote code execution.
The technical implementation of this vulnerability aligns with CWE-77, which specifically addresses command injection flaws where untrusted data is incorporated into system commands without proper sanitization or validation. The vulnerability operates through the web management interface, where the router's apply.cgi script processes user input without adequate filtering mechanisms. When an attacker submits malicious payloads through the designated parameters, the system fails to properly validate or escape the input before incorporating it into shell commands, creating a direct pathway for command execution. The affected parameters suggest this vulnerability may be related to wireless transmission settings or radio control functions, which are particularly sensitive areas within router firmware due to their direct system interaction requirements.
The operational impact of CVE-2023-31740 extends beyond simple privilege escalation to encompass full system compromise and potential network infiltration. Once an attacker gains web management privileges and successfully exploits this vulnerability, they can execute arbitrary shell commands with the privileges of the web server process, typically running with elevated system permissions. This capability enables attackers to install malware, modify network configurations, establish persistent backdoors, or use the compromised router as a pivot point for attacking other devices within the local network. The vulnerability is particularly concerning because it requires only web management access, which may be obtained through various means including weak credentials, session hijacking, or other pre-existing vulnerabilities, making the exploitation chain relatively accessible.
From an adversarial perspective, this vulnerability maps directly to ATT&CK technique T1059.001 for command and scripting interpreter, specifically shell scripting, and T1068 for exploit for privilege escalation. The attack surface is further expanded through potential use of techniques like T1566 for initial access and T1071 for application layer protocol usage. Organizations should implement immediate mitigations including firmware updates from Linksys, network segmentation to isolate affected devices, and monitoring for suspicious web management activity. The vulnerability also highlights the importance of secure coding practices and input validation, particularly in embedded systems where resource constraints may lead to insufficient security controls. Regular firmware updates and vulnerability assessments remain critical defensive measures against such persistent threats in network infrastructure devices.
The broader implications of this vulnerability underscore the need for comprehensive security testing of embedded network devices, particularly those handling administrative functions. The vulnerability demonstrates how seemingly isolated parameter handling flaws can create complete system compromise scenarios, emphasizing the importance of defense-in-depth strategies. Security professionals should also consider implementing network monitoring solutions that can detect anomalous command execution patterns and unauthorized administrative access attempts. This vulnerability serves as a reminder that network infrastructure devices often receive insufficient security attention compared to traditional computing systems, making them attractive targets for sophisticated adversaries seeking persistent access to network environments.