CVE-2026-76582 in TEW-821DAP
Summary
by MITRE • 08/20/2026
A vulnerability was determined in TRENDnet TEW-821DAP 2.2.01b05. Affected is the function popen/system of the file /cgi-bin/ping.cgi of the component ssi. Executing a manipulation of the argument ipaddr can lead to command injection. It is possible to launch the attack remotely. The exploit has been publicly disclosed and may be utilized.
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Analysis
by VulDB Data Team • 08/20/2026
The TRENDnet TEW-821DAP wireless access point, specifically version 2.2.01b05, contains a critical security flaw within its server-side include (SSI) component that allows for remote command injection. This vulnerability resides in the ping.cgi script located at /cgi-bin/ping.cgi, which is responsible for handling network diagnostic requests from users or administrators. The core technical issue stems from the improper validation and sanitization of user-supplied input passed to the ipaddr argument. When this parameter is processed, it is directly concatenated into system commands without adequate filtering, creating a classic command injection vector that enables an attacker to execute arbitrary operating system commands with the privileges of the web server process.
This flaw aligns closely with Common Weakness Enumeration (CWE) categories such as CWE-78 Improper Neutralization of Special Elements used in an OS Command and CWE-94 Improper Control of Generation of Code, which highlight failures in input validation that lead to unintended code execution. The presence of the popen or system function calls within the CGI script indicates a fundamental design error where external data is treated as executable code rather than safe string literals. Because this functionality is exposed via an HTTP interface, the vulnerability can be exploited remotely by any network user who has access to the device's management interface, significantly expanding the attack surface beyond local physical access scenarios.
The operational impact of exploiting this command injection vulnerability is severe and potentially catastrophic for network security. An attacker could leverage this flaw to gain full control over the embedded Linux operating system running on the access point. This level of compromise allows for the installation of persistent malware, such as botnet agents or rootkits, turning the device into a node in larger distributed denial-of-service networks. Furthermore, the compromised device can be used as a pivot point to launch attacks against other devices within the local network segment, facilitating lateral movement and potential data exfiltration from connected endpoints that trust the access point for routing services.
Given that this exploit has been publicly disclosed and is actively utilized in the wild, immediate remediation actions are required to mitigate risk. The most effective mitigation strategy involves applying any available firmware updates provided by TRENDnet that address input validation issues within the ping.cgi script. If no patch is currently available, administrators should consider restricting access to the management interface through IP whitelisting or disabling remote administration features entirely until a fix can be deployed. Additionally, implementing network segmentation to isolate IoT devices from critical internal infrastructure can limit the blast radius of such an exploitation event in accordance with defense-in-depth principles outlined by MITRE ATT&CK techniques related to initial access and execution on local systems.