CVE-2023-33671 in AC8
Summary
by MITRE • 06/02/2023
Tenda AC8V4.0-V16.03.34.06 was discovered to contain a stack overflow via the deviceId parameter in the saveParentControlInfo function.
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Analysis
by VulDB Data Team • 01/06/2026
The vulnerability identified as CVE-2023-33671 represents a critical stack overflow flaw within the Tenda AC8V4.0-V16.03.34.06 router firmware, specifically manifesting in the saveParentControlInfo function. This issue arises from inadequate input validation mechanisms that fail to properly sanitize the deviceId parameter, creating a pathway for malicious actors to exploit memory corruption vulnerabilities. The affected device model operates under the broader context of consumer-grade networking equipment that handles sensitive parental control configurations, making this vulnerability particularly concerning for household security systems. The stack overflow condition occurs when the firmware processes unvalidated user input, leading to potential arbitrary code execution and complete system compromise.
The technical exploitation of this vulnerability stems from the improper handling of string inputs within the saveParentControlInfo function, which lacks proper bounds checking mechanisms. When an attacker submits a crafted deviceId parameter exceeding the allocated stack buffer size, the overflow corrupts adjacent memory locations including return addresses and function pointers. This memory corruption directly violates the fundamental principles of secure programming practices and aligns with CWE-121, which describes stack-based buffer overflow conditions. The vulnerability's impact extends beyond simple memory corruption as it enables attackers to manipulate the program's execution flow, potentially leading to privilege escalation and persistent system compromise. The attack surface is particularly significant given that parental control configurations often contain sensitive user data and system access credentials.
The operational implications of this vulnerability present substantial risks to both individual users and network security infrastructure. Compromised routers can serve as entry points for broader network infiltration, allowing attackers to establish persistent backdoors, monitor network traffic, or redirect traffic through malicious endpoints. The vulnerability affects devices that are typically deployed in residential and small office environments where network security awareness may be limited, increasing the potential for widespread exploitation. According to ATT&CK framework category T1071.004, this vulnerability enables command and control communications, while T1068 represents the privilege escalation potential that could occur through successful exploitation. Organizations relying on these devices for network security may experience complete loss of network integrity and confidentiality, particularly in environments where parental control settings are used to manage access to sensitive online content.
Mitigation strategies for CVE-2023-33671 should prioritize immediate firmware updates from Tenda, as the vendor has likely released patches addressing the specific buffer overflow condition. Network administrators should implement network segmentation to limit the impact of potential exploitation and deploy intrusion detection systems capable of identifying malformed requests targeting the saveParentControlInfo endpoint. Additional protective measures include disabling unnecessary services, implementing strong access controls for router management interfaces, and establishing regular firmware update policies for all network equipment. Security monitoring should focus on identifying unusual patterns in device configuration changes and unauthorized access attempts to parental control functions. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly those handling user-provided data in network infrastructure devices. Organizations should also consider conducting vulnerability assessments to identify similar issues in other network equipment and implement comprehensive security testing protocols for all firmware components.