CVE-2022-38325 in AC15
Summary
by MITRE • 09/16/2022
Tenda AC15 WiFi Router V15.03.05.19_multi and AC18 WiFi Router V15.03.05.19_multi were discovered to contain a buffer overflow via the filePath parameter at /goform/expandDlnaFile.
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Analysis
by VulDB Data Team • 09/16/2022
The vulnerability identified as CVE-2022-38325 affects Tenda AC15 and AC18 WiFi routers running firmware versions V15.03.05.19_multi. This issue manifests as a buffer overflow condition within the web interface handling of the expandDlnaFile function, specifically when processing the filePath parameter. The affected routers are part of Tenda's consumer-grade networking equipment designed for home and small office environments, making them widely deployed across various network infrastructures.
The technical flaw occurs within the /goform/expandDlnaFile endpoint which processes file path inputs without adequate bounds checking or input validation. When an attacker submits a specially crafted filePath parameter containing excessive data, the router's processing function fails to properly handle the input length, leading to a buffer overflow condition. This vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation in web applications. The attack vector is particularly concerning as it operates through the web management interface, requiring no local access or authentication.
The operational impact of this vulnerability extends beyond simple denial of service conditions. An attacker who successfully exploits this buffer overflow could potentially execute arbitrary code on the affected router, leading to complete system compromise. This would allow unauthorized individuals to gain administrative control over the network device, potentially enabling them to modify router configurations, intercept network traffic, or establish persistent access points within the network infrastructure. The vulnerability creates a significant risk for home users and small businesses that rely on these devices for network connectivity, as the compromised router could serve as a gateway for broader network attacks.
Mitigation strategies should focus on immediate firmware updates from Tenda, as the vendor has likely released patches addressing this specific vulnerability. Network administrators should also implement network segmentation and access controls to limit exposure of these devices to untrusted networks. The vulnerability demonstrates the importance of secure coding practices in embedded systems and highlights the need for proper input validation and bounds checking in web application interfaces. Security monitoring should include detection of unusual traffic patterns to the /goform/expandDlnaFile endpoint, and network defenders should consider implementing web application firewalls to filter malicious input parameters. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, emphasizing the need for comprehensive security measures across network infrastructure devices.