CVE-2026-4497 in WA300
Summary
by MITRE • 03/20/2026
A vulnerability was determined in Totolink WA300 5.2cu.7112_B20190227. Affected by this issue is the function recvUpgradeNewFw of the file /cgi-bin/cstecgi.cgi. This manipulation causes os command injection. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized.
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Analysis
by VulDB Data Team • 03/27/2026
The vulnerability identified as CVE-2026-4497 affects the Totolink WA300 router model running firmware version 5.2cu.7112_B20190227. This issue resides within the cstecgi.cgi script which handles various administrative functions through the web interface. The specific function recvUpgradeNewFw demonstrates a critical security flaw that allows remote attackers to execute arbitrary operating system commands on the affected device. The vulnerability represents a command injection flaw that can be exploited without authentication, making it particularly dangerous for networked environments where such devices are deployed.
The technical implementation of this vulnerability stems from improper input validation within the recvUpgradeNewFw function. When the router processes firmware upgrade requests through the cgi-bin interface, it fails to properly sanitize user-supplied data before incorporating it into system commands. This allows an attacker to inject malicious commands that get executed with the privileges of the web server process, typically running with elevated permissions on the device. The flaw directly maps to CWE-77 which describes improper neutralization of special elements used in OS commands, a category that includes command injection vulnerabilities. The attack vector is particularly concerning as it enables remote exploitation through the web interface without requiring any prior authentication credentials.
The operational impact of this vulnerability extends beyond simple unauthorized access to potentially full system compromise. An attacker who successfully exploits this command injection flaw could gain complete control over the router's operating system, allowing them to modify network configurations, redirect traffic, install malware, or use the device as a pivot point for attacking other systems within the local network. The publicly disclosed exploit means that this vulnerability is immediately actionable by threat actors, increasing the risk of widespread exploitation. This aligns with ATT&CK technique T1059.001 which covers command and scripting interpreter usage, specifically targeting the execution of commands through vulnerable web applications. The compromised device could serve as a persistent backdoor or be used to launch further attacks against internal network resources.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from the vendor if available, as the manufacturer would have likely released a patch addressing the command injection flaw. Network segmentation and firewall rules should be implemented to restrict access to the router's administrative interface to only trusted sources. Additional protective measures include disabling unnecessary services, implementing strong access controls, and monitoring network traffic for suspicious command execution patterns. Organizations should also consider deploying intrusion detection systems to identify exploitation attempts and maintain comprehensive network monitoring to detect unauthorized access attempts. The vulnerability highlights the importance of proper input validation and output encoding in web applications, particularly those handling user input that may be used in system command execution contexts. Security teams should conduct thorough network assessments to identify all affected devices and implement layered security controls to minimize the attack surface and reduce the likelihood of successful exploitation.