CVE-2022-40103 in Tenda
Summary
by MITRE • 09/23/2022
Tenda i9 v1.0.0.8(3828) was discovered to contain a buffer overflow via the formSetAutoPing function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted string.
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Analysis
by VulDB Data Team • 10/23/2022
The vulnerability identified as CVE-2022-40103 affects the Tenda i9 router model running firmware version 1.0.0.8(3828) and represents a critical buffer overflow condition within the formSetAutoPing function. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing. The buffer overflow occurs when the device receives a malformed string through the auto ping configuration interface, which is commonly used for network monitoring and connectivity verification purposes. The vulnerability resides in the router's web management interface where administrators configure automatic ping settings to monitor network connectivity. When an attacker submits a specially crafted string exceeding the allocated buffer size, the device's memory management becomes compromised, leading to unpredictable behavior and system instability.
The technical exploitation of this vulnerability demonstrates characteristics consistent with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The formSetAutoPing function likely employs fixed-size buffers to store configuration parameters without proper validation of input length or content, creating an opportunity for attackers to manipulate the program flow through memory corruption. This type of vulnerability falls under the broader category of memory safety issues that have been extensively documented in cybersecurity literature and represent one of the most common attack vectors in embedded systems and network devices. The DoS condition manifests when the buffer overflow causes the application to crash or terminate unexpectedly, rendering the router's management interface inaccessible and potentially disrupting network connectivity for all connected devices.
From an operational perspective, this vulnerability presents significant risks to network infrastructure security and reliability. The DoS attack capability means that unauthorized individuals can effectively disable critical network monitoring functions without requiring authentication, potentially leading to extended network outages and service disruption. Network administrators may experience complete loss of device management capabilities, forcing them to perform manual recovery procedures including physical device reboot or firmware reinstallation. The attack surface is particularly concerning because many network administrators rely on automated ping monitoring for network health assessment, making this vulnerability particularly impactful for organizations that depend on continuous network availability. The vulnerability also aligns with ATT&CK technique T1499.004, which covers network disruption through denial of service attacks, and represents a critical weakness in the device's defensive posture against unauthorized access attempts.
Mitigation strategies for CVE-2022-40103 should prioritize immediate firmware updates from Tenda's official sources, as the manufacturer has likely released patches addressing the buffer overflow condition. Network segmentation and access control measures can help reduce the attack surface by limiting direct access to the router's management interface from untrusted networks. Implementing network monitoring solutions that can detect unusual traffic patterns or repeated connection attempts may provide early warning of exploitation attempts. Organizations should also consider disabling unnecessary services and features on the router, particularly those related to automated ping functionality that could be exploited. The vulnerability highlights the importance of regular security assessments for embedded network devices and demonstrates the necessity of implementing robust input validation mechanisms in all network-facing applications. Additionally, network administrators should establish procedures for maintaining current firmware versions and conducting routine security audits to identify similar vulnerabilities in other network infrastructure components.