CVE-2023-40802 in AC23
Summary
by MITRE • 08/25/2023
The get_parentControl_list_Info function does not verify the parameters entered by the user, causing a post-authentication heap overflow vulnerability in Tenda AC23 v16.03.07.45_cn
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability identified as CVE-2023-40802 represents a critical heap overflow condition within the Tenda AC23 router firmware version 16.03.07.45_cn. This issue manifests in the get_parentControl_list_Info function which fails to properly validate input parameters provided by authenticated users. The absence of parameter validation creates a pathway for malicious actors who have already established authentication credentials to exploit this weakness. The vulnerability specifically affects the heap memory management of the affected device, potentially allowing for arbitrary code execution or system instability. The heap overflow occurs because the function processes user-supplied data without adequate bounds checking or sanitization, making it susceptible to buffer overrun conditions that can corrupt adjacent memory locations.
The technical flaw stems from inadequate input validation mechanisms within the parent control functionality of the router's web interface. When an authenticated user submits parameters to the get_parentControl_list_Info endpoint, the system accepts these inputs without proper verification of their length, format, or content. This vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, though in this case the heap is the affected memory region. The operational impact extends beyond simple memory corruption as the heap overflow can be leveraged to manipulate program execution flow, potentially allowing attackers to inject malicious code or escalate privileges within the device's operating environment. The post-authentication requirement means that attackers must first establish valid credentials, typically through credential guessing, phishing, or exploitation of other authentication vulnerabilities, before they can target this specific heap overflow.
The security implications of this vulnerability are significant for network infrastructure devices, particularly those used in residential and small office environments where Tenda routers are commonly deployed. The heap overflow can result in denial of service conditions where the router becomes unresponsive or crashes entirely, disrupting network connectivity for all connected devices. More concerning is the potential for remote code execution, which would allow attackers to gain full control over the device and potentially use it as a pivot point for attacking other systems within the local network. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, where an attacker could execute arbitrary commands on the compromised device. The impact extends to data privacy and network security as the compromised router could be used to monitor traffic, redirect requests, or serve as a persistent backdoor for ongoing access.
Mitigation strategies for this vulnerability should include immediate firmware updates from Tenda to address the parameter validation flaw in the get_parentControl_list_Info function. Network administrators should implement strict access controls and monitor authentication attempts for suspicious activity that might indicate credential compromise attempts. The principle of least privilege should be applied to router management interfaces, limiting access to only authorized personnel and implementing multi-factor authentication where possible. Network segmentation techniques can help contain potential exploitation by isolating critical systems from devices that may be compromised. Regular security audits and vulnerability assessments should be conducted to identify similar parameter validation issues in other firmware components, as the root cause of this vulnerability suggests a broader pattern of insufficient input sanitization that may affect other functions within the same software ecosystem. Additionally, implementing intrusion detection systems that monitor for unusual parameter patterns in web requests can provide early warning of potential exploitation attempts.