CVE-2026-7244 in A8000RU
Summary
by MITRE • 04/28/2026
A security flaw has been discovered in Totolink A8000RU 7.1cu.643_b20200521. The impacted element is the function setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument merge results in os command injection. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks.
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Analysis
by VulDB Data Team • 05/09/2026
The vulnerability identified in Totolink A8000RU firmware version 7.1cu.643_b20200521 represents a critical command injection flaw within the device's web interface management system. This security weakness resides in the CGI Handler component, specifically within the setWiFiEasyGuestCfg function located in the /cgi-bin/cstecgi.cgi file. The vulnerability stems from inadequate input validation and sanitization of user-supplied parameters, creating an exploitable condition that allows remote attackers to execute arbitrary operating system commands on the affected device. The flaw manifests when manipulating the merge argument parameter, which bypasses proper security controls and directly influences the system's command execution pipeline. This type of vulnerability falls under the category of CWE-77 and CWE-94, representing command injection and code injection respectively, which are fundamental security weaknesses that enable attackers to compromise system integrity and execute malicious code with the privileges of the affected service.
The operational impact of this vulnerability extends far beyond simple remote code execution, as it provides attackers with complete control over the affected router's operating system. Once exploited, the attacker can manipulate network configurations, access sensitive data, redirect traffic, or establish persistent backdoors within the device. The remote exploitability of this flaw means that attackers do not require physical access to the device or network proximity to execute attacks, making it particularly dangerous for enterprise and residential networks. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically the use of OS command injection to execute malicious payloads. The public availability of exploit code significantly increases the risk profile, as it eliminates the need for advanced technical skills to leverage the vulnerability, potentially enabling widespread exploitation across vulnerable installations.
Mitigation strategies for this vulnerability require immediate firmware updates from the vendor to address the input validation flaws in the CGI Handler component. Network administrators should implement network segmentation and access controls to limit potential attack vectors, while monitoring network traffic for suspicious command execution patterns. The implementation of web application firewalls and input validation controls can provide additional protection layers against similar attacks. Organizations should also conduct comprehensive vulnerability assessments to identify other potentially affected devices within their network infrastructure, as this type of flaw often indicates broader security weaknesses in embedded systems. Regular security audits of network devices, particularly those with web management interfaces, are essential to prevent similar vulnerabilities from being exploited. The vulnerability demonstrates the critical importance of proper input sanitization and the principle of least privilege in embedded system security design, as recommended by industry standards including NIST SP 800-160 and ISO/IEC 27030.