CVE-2022-38568 in Tenda
Summary
by MITRE • 08/28/2022
Tenda M3 V1.0.0.12(4856) was discovered to contain a heap buffer overflow vulnerability in the function formSetFixTools. This vulnerability allows attackers to cause a Denial of Service (DoS) via the hostname parameter.
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Analysis
by VulDB Data Team • 10/09/2022
The heap buffer overflow vulnerability identified in Tenda M3 router firmware version 1.0.0.12(4856) represents a critical security flaw within the device's web interface handling mechanism. This vulnerability specifically manifests within the formSetFixTools function, which processes user input through the hostname parameter. The flaw stems from inadequate bounds checking and memory management practices during the processing of network configuration data, creating an exploitable condition that can be leveraged by remote attackers to disrupt normal device operations.
The technical implementation of this vulnerability involves the improper handling of user-supplied data within the router's embedded web server component. When the hostname parameter is submitted through the web interface, the formSetFixTools function fails to validate the input length against the allocated heap memory buffer. This discrepancy allows an attacker to provide input data that exceeds the predetermined buffer size, resulting in memory corruption that overflows into adjacent heap memory regions. The vulnerability falls under the Common Weakness Enumeration category of CWE-121, which specifically addresses stack and heap buffer overflow conditions that can lead to arbitrary code execution or system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can potentially be exploited to cause complete system crashes or restarts of the affected router. Network administrators and end users may experience intermittent connectivity issues, complete network outages, or forced device reboots that disrupt business operations and compromise network availability. The remote exploitability of this flaw means that attackers do not require physical access to the device or local network presence to execute the attack, making it particularly dangerous in enterprise and residential network environments where such devices are commonly deployed.
From an attack framework perspective, this vulnerability aligns with the MITRE ATT&CK framework's T1203 category for Exploitation for Client Execution, as it enables remote code execution through web interface manipulation. The attack surface is particularly concerning given that many routers lack robust input validation mechanisms and are often exposed to external networks through NAT configurations. Security professionals should note that this vulnerability represents a classic example of insufficient input sanitization that can be exploited to cause system instability and potentially provide a foothold for more sophisticated attacks.
Mitigation strategies for this vulnerability should include immediate firmware updates from Tenda to address the heap buffer overflow condition. Network administrators should also implement network segmentation and access controls to limit exposure of affected devices to untrusted networks. Additional protective measures include deploying web application firewalls to filter malicious input parameters and monitoring network traffic for suspicious hostname parameter submissions. Regular vulnerability assessments of network infrastructure components and maintaining updated security patches represent essential defensive practices to prevent exploitation of similar buffer overflow vulnerabilities in network equipment.