CVE-2026-86152 in CP3
Summary
by MITRE • 09/06/2026
A flaw has been found in Tenda CP3 27.5.57.101. The impacted element is the function CAutoAddWifi::ThreadProc of the file Functions/AutoAddWifi.cpp of the component Kylin. Executing a manipulation can lead to os command injection. The attack may be launched remotely.
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Analysis
by VulDB Data Team • 09/06/2026
The vulnerability identified in Tenda CP3 firmware version 27.5.57.101 represents a critical security flaw within the device's network management subsystem, specifically located in the Kylin component. This issue resides in the CAutoAddWifi::ThreadProc function found within the Functions/AutoAddWifi.cpp source file. The presence of this vulnerability indicates that the software fails to properly validate or sanitize user-supplied input before passing it to system-level commands for execution. Such a design oversight is characteristic of insecure command construction practices where dynamic data from external sources, potentially including network packets received by the device, are directly interpolated into operating system shell commands without adequate filtering or escaping mechanisms.
From a technical perspective, this flaw constitutes an OS Command Injection vulnerability, which aligns with Common Weakness Enumeration identifier CWE-78. The root cause lies in the improper neutralization of special elements used in operating system commands. When the CAutoAddWifi::ThreadProc function processes input related to wireless network configuration or auto-addition procedures, it likely concatenates user-controlled strings directly into a command line interface call. An attacker who can interact with this specific endpoint or service vector can inject malicious shell metacharacters such as semicolons, pipes, or backticks. These characters allow the injection of additional commands that are then executed by the underlying operating system with the privileges associated with the vulnerable process.
The operational impact of this vulnerability is severe due to its remote exploitability. Because the attack can be launched remotely, an adversary does not need physical access to the device nor prior authentication credentials if the affected service is exposed on a network interface accessible from untrusted zones such as the internet or public Wi-Fi networks. Successful exploitation allows for arbitrary command execution on the host system running the Tenda CP3 firmware. This effectively results in full compromise of the IoT device, enabling attackers to modify configurations, install persistent malware, use the device as part of a botnet like Mirai, or pivot into other segments of the local network where sensitive data resides. The ability to execute commands remotely transforms what might otherwise be a configuration error into a significant threat vector for widespread automated attacks targeting vulnerable IoT infrastructure.
In terms of industry classification frameworks, this vulnerability maps directly to MITRE ATT&CK technique T1059 Command and Scripting Interpreter, specifically the Unix Shell sub-technique (T1059.004). This categorization highlights how attackers leverage native system interpreters to execute malicious payloads after gaining initial access through the injection flaw. The remote nature of the attack also aligns with ATT&CK tactic TA0001 Initial Access, as it provides a pathway for adversaries to establish a foothold in an otherwise isolated or semi-isolated network environment typical of IoT deployments.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary solution is the application of vendor-provided firmware updates that patch the CAutoAddWifi::ThreadProc function by implementing strict input validation and output encoding. Developers should avoid passing unsanitized user input directly to system commands; instead, they should use API calls that do not invoke a shell interpreter whenever possible. If command execution is unavoidable, inputs must be rigorously validated against an allowlist of expected characters and values. For organizations currently operating vulnerable devices, network segmentation is recommended to isolate IoT traffic from critical corporate or residential networks until patches can be applied. Additionally, disabling unnecessary remote management features reduces the attack surface available for exploitation by external actors scanning for known vulnerabilities in embedded Linux-based systems like those used in Tenda routers.