CVE-2026-2930 in A18
Summary
by MITRE • 02/22/2026
A vulnerability was identified in Tenda A18 15.13.07.13. The affected element is the function webCgiGetUploadFile of the file /cgi-bin/UploadCfg of the component Httpd Service. Such manipulation of the argument boundary leads to stack-based buffer overflow. The attack can be executed remotely. The exploit is publicly available and might be used.
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Analysis
by VulDB Data Team • 02/23/2026
The vulnerability identified in Tenda A18 firmware version 15.13.07.13 represents a critical stack-based buffer overflow flaw within the Httpd Service component. This issue manifests specifically in the webCgiGetUploadFile function located within the /cgi-bin/UploadCfg file, making it a prime target for remote exploitation. The vulnerability stems from inadequate input validation of the boundary argument parameter, which allows attackers to manipulate memory allocation during function execution. Such buffer overflow conditions typically occur when programs write more data to a fixed-length buffer than it can accommodate, leading to corruption of adjacent memory locations including stack canaries, return addresses, and function pointers. The exposure of this vulnerability through the web interface of the Httpd Service creates a direct attack vector that can be leveraged from external networks without requiring physical access or authentication credentials.
The remote exploitability of this vulnerability significantly amplifies its threat level, as attackers can initiate malicious payloads from anywhere on the internet without needing to be physically present at the device location. This characteristic places the affected Tenda A18 devices at substantial risk, particularly in environments where such routers are exposed to public networks or when they serve as gateways for corporate or residential networks. The publicly available exploit further compounds the danger, as it eliminates the need for advanced technical skills or custom development to launch attacks against vulnerable systems. Attackers can potentially leverage this vulnerability to execute arbitrary code on the affected device, which could lead to complete system compromise, persistent backdoor installation, or use as a foothold for broader network infiltration activities.
From a technical perspective, this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses situations where insufficient bounds checking allows data to overwrite adjacent stack memory regions. The ATT&CK framework categorizes this type of vulnerability under T1210 Exploitation for Credential Access and T1059 Command and Scripting Interpreter, as successful exploitation would likely enable attackers to execute commands on the compromised device and potentially escalate privileges to gain deeper system access. The operational impact extends beyond simple device compromise, as affected routers serve as fundamental network infrastructure components that could be used to redirect traffic, monitor communications, or provide attackers with persistent access points for lateral movement within network environments. Organizations using these devices should immediately implement mitigation strategies including firmware updates, network segmentation, and monitoring for suspicious network activity. The vulnerability's public exploit availability necessitates urgent remediation efforts to prevent widespread exploitation across affected installations.
The broader implications of this vulnerability highlight the critical importance of secure coding practices and regular firmware updates in network infrastructure devices. Many IoT and networking devices suffer from similar memory corruption vulnerabilities due to insufficient input validation and buffer management, making them attractive targets for automated exploitation campaigns. Network administrators should consider implementing network-based intrusion detection systems to monitor for exploitation attempts and maintain comprehensive inventory tracking of all network devices to ensure timely patch deployment. The vulnerability also underscores the need for manufacturers to provide timely security updates and clear communication about known vulnerabilities to maintain device security throughout their operational lifecycle.