CVE-2023-41560 in AC9
Summary
by MITRE • 08/30/2023
Tenda AC9 V3.0 V15.03.06.42_multi was discovered to contain a stack overflow via parameter firewallEn at url /goform/SetFirewallCfg.
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Analysis
by VulDB Data Team • 02/01/2026
The vulnerability identified as CVE-2023-41560 affects the Tenda AC9 router model running firmware version V3.0 V15.03.06.42_multi and represents a critical stack overflow condition that can be exploited through a specifically crafted HTTP request. This vulnerability resides within the web management interface of the device, specifically targeting the firewall configuration functionality through the parameter named firewallEn which is processed at the url path /goform/SetFirewallCfg. The stack overflow occurs when the device fails to properly validate or sanitize input parameters received through this particular web form, creating an exploitable condition that allows remote attackers to manipulate the device's memory structure.
The technical flaw manifests as a classic stack-based buffer overflow vulnerability, where an attacker can supply excessive input data to the firewallEn parameter that exceeds the allocated buffer space on the stack. This condition is classified under CWE-121 as a stack-based buffer overflow, which occurs when a program writes data beyond the bounds of a fixed-length buffer allocated on the stack. The vulnerability is particularly concerning because it allows for arbitrary code execution in the context of the device's operating system, potentially enabling attackers to gain full administrative control over the router. The attack vector is remote and requires no authentication, making it especially dangerous in networked environments where these devices are commonly deployed.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it can enable attackers to establish persistent backdoors, modify network configurations, redirect traffic, or even use the compromised device as a pivot point for further attacks within the local network. This represents a significant threat to network security since routers serve as critical gateways and often have elevated privileges within network infrastructures. The vulnerability can be exploited through simple web requests, making it accessible to attackers with minimal technical expertise. According to ATT&CK framework tactic TA0001 (Initial Access) and technique T1190 (Exploit Public-Facing Application), this vulnerability provides a direct path for attackers to establish a foothold in target networks through exploitation of publicly accessible web applications.
Mitigation strategies for CVE-2023-41560 should include immediate firmware updates from Tenda to address the stack overflow condition, proper input validation and sanitization within the affected web application, and network segmentation to limit the attack surface. Network administrators should implement monitoring for unusual traffic patterns or unauthorized configuration changes to the affected devices, while also considering disabling unnecessary web management interfaces when not actively required. The vulnerability highlights the importance of secure coding practices and proper input validation, particularly for web applications that handle user-supplied data. Organizations should also conduct regular vulnerability assessments of their network infrastructure to identify similar issues in other devices, as this type of stack overflow vulnerability is commonly found in embedded systems and network appliances where memory safety checks are often insufficient. Additionally, implementing network access controls and firewall rules to restrict access to administrative interfaces can provide defense-in-depth measures against exploitation attempts.