CVE-2026-71908 in VigorAP
Summary
by MITRE • 08/24/2026
Multiple DrayTek VigorAP models contain a command injection vulnerability in the mesh_start_speed_test function. The vulnerability is caused by insufficient sanitization of the meshdevice_index and meshdevice_ip fields before command execution. A remote attacker can trigger this vulnerability via crafted input to execute arbitrary commands with root privileges. Exploitation requires valid administrative credentials for the device's web management interface.
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Analysis
by VulDB Data Team • 08/24/2026
The DrayTek VigorAP series, a line of enterprise-grade wireless access points widely deployed in corporate and institutional networks, contains a critical command injection vulnerability within its mesh network configuration module. This flaw resides specifically in the mesh_start_speed_test function, which is responsible for initiating diagnostic speed tests between mesh nodes to ensure optimal network performance and connectivity stability. The root cause of this vulnerability lies in insufficient input validation and sanitization mechanisms applied to two specific parameters: meshdevice_index and meshdevice_ip. These fields are intended to accept integer indices representing device identifiers and IP addresses respectively, but the underlying implementation fails to strictly enforce type constraints or escape special characters before passing these values into system-level command execution routines. This lack of rigorous boundary checking allows an attacker to inject malicious shell commands that bypass standard input expectations, effectively turning a diagnostic feature into a vector for remote code execution.
From a technical perspective, this vulnerability is classified under CWE-78 Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The severity of the flaw is exacerbated by the fact that the affected function operates with root privileges within the device's operating system environment. When a crafted payload containing shell metacharacters such as semicolons, pipes, or backticks is submitted via the meshdevice_ip field, the application executes these commands directly on the host OS without restriction. This architectural design flaw means that any command injected through this vector inherits the highest level of administrative privileges available to the device's software stack. Consequently, an attacker does not need to exploit privilege escalation techniques post-exploitation because they are granted immediate root access upon successful injection.
The operational impact of this vulnerability is severe and far-reaching for organizations relying on DrayTek VigorAP devices for their wireless infrastructure. A remote authenticated attacker can achieve complete compromise of the affected device, leading to unauthorized access to sensitive network data, modification of firmware configurations, or use of the compromised access point as a pivot node for further attacks against internal systems. The ability to execute arbitrary commands with root privileges allows an adversary to install persistent backdoors, exfiltrate configuration files containing credentials and encryption keys, or disrupt service availability by manipulating system processes. This represents a significant risk to network integrity and confidentiality, particularly in environments where these access points serve as gateways between trusted internal networks and external untrusted zones.
Exploitation of this vulnerability requires valid administrative credentials for the device's web management interface, which classifies it under CWE-287 Improper Authentication within the context of initial access requirements. While this requirement limits the attack surface to authenticated users rather than fully remote anonymous attackers, it does not mitigate the severity given that insider threats or compromised admin accounts are common vectors in enterprise environments. The vulnerability aligns with MITRE ATT&CK technique T1059 Command and Scripting Interpreter, specifically regarding how adversaries use system commands to interact with operating systems during post-exploitation phases. It also relates to T1190 Exploit Public-Facing Application if the management interface is exposed to untrusted networks without adequate access controls or multi-factor authentication.
To mitigate this risk, organizations must immediately apply vendor-provided firmware updates that address the input sanitization flaws in the mesh_start_speed_test function. Until patches are available, administrators should restrict access to the web management interface by limiting it to trusted IP addresses using firewall rules and disabling unnecessary services such as SSH or Telnet if not required for operations. Implementing strict network segmentation ensures that even if an attacker gains administrative credentials on one segment, they cannot easily reach the management interfaces of critical infrastructure devices. Additionally, deploying intrusion detection systems with signatures capable of detecting command injection patterns in HTTP traffic can provide early warning indicators of exploitation attempts. Regular auditing of user accounts and enforcement of strong password policies further reduces the likelihood of credential compromise leading to this specific vulnerability being exploited.