CVE-2026-3227 in TL-WR802N v4
Summary
by MITRE • 03/16/2026
A command injection vulnerability was identified in TP-Link TL-WR802N v4, TL-WR841N v14, and TL-WR840N v6 due to improper neutralization of special elements used in an OS command. In the router configuration import function allows an authenticated attacker to upload a crafted configuration file that results in execution of OS commands with root privileges during port-trigger processing. Successful exploitation allows an authenticated attacker to execute system commands with root privileges, leading to full device compromise.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/16/2026
This command injection vulnerability exists in TP-Link wireless routers including models TL-WR802N v4, TL-WR841N v14, and TL-WR840N v6 due to inadequate input validation in the configuration import functionality. The flaw resides in how the device processes port-triggering configurations during the import process, where special command characters are not properly sanitized or escaped before being executed as operating system commands. The vulnerability falls under CWE-77 which specifically addresses command injection flaws in software systems. An authenticated attacker with access to the router's administrative interface can exploit this weakness by uploading a malicious configuration file containing OS command injection payloads.
The technical implementation of this vulnerability occurs within the router's firmware where the configuration import function fails to neutralize special characters such as semicolons, ampersands, or backticks that are commonly used to chain commands in shell environments. When the router processes these malicious configurations during port-triggering operations, it directly executes the embedded commands without proper sanitization, creating a path for arbitrary code execution. This represents a critical security flaw that allows attackers to bypass authentication mechanisms and gain root-level privileges on the affected devices. The exploitation process typically involves crafting a configuration file that includes shell commands within the port-triggering parameters, which then get executed with the highest privilege level available to the router's operating system.
The operational impact of this vulnerability is severe as it enables complete compromise of the affected routers. Once exploited, attackers can execute arbitrary system commands with root privileges, potentially allowing them to modify router configurations, install backdoors, redirect network traffic, or even use the compromised devices as entry points for further attacks within the local network. The vulnerability affects the core functionality of the router's configuration management system, making it a critical target for attackers seeking persistent access to network infrastructure. From an attack perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, representing a direct path to system compromise and lateral movement within network environments.
Mitigation strategies for this vulnerability should include immediate firmware updates from TP-Link to address the command injection flaw, proper network segmentation to limit access to router administrative interfaces, and implementation of network monitoring to detect unusual command execution patterns. Organizations should also enforce strict access controls and authentication measures for router management interfaces, implement network access control lists to restrict configuration import operations, and regularly audit router configurations for suspicious entries. The vulnerability demonstrates the critical importance of input validation in embedded systems and highlights the need for proper sanitization of user-supplied data before processing within operating system contexts. Security practitioners should also consider implementing network intrusion detection systems that can identify attempts to exploit similar command injection vulnerabilities in network infrastructure devices.