CVE-2024-3905 in AC500
Summary
by MITRE • 04/17/2024
A vulnerability was found in Tenda AC500 2.0.1.9(1307). It has been classified as critical. This affects the function R7WebsSecurityHandler of the file /goform/execCommand. The manipulation of the argument password leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-261141 was assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 01/22/2025
This critical vulnerability exists in the Tenda AC500 router firmware version 2.0.1.9(1307) and represents a stack-based buffer overflow flaw in the R7WebsSecurityHandler function within the /goform/execCommand file. The vulnerability is triggered when the password argument is manipulated during function execution, creating an exploitable condition that allows attackers to overwrite adjacent memory locations on the stack. The flaw's classification as critical stems from its remote exploitability, meaning that an attacker can initiate the attack without physical access to the device, making it particularly dangerous for networked environments. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is a well-documented weakness in software security that occurs when a program writes data beyond the bounds of a fixed-length buffer allocated on the stack. The vulnerability's public disclosure through identifier VDB-261141 indicates that malicious actors have already developed exploit code, increasing the risk to affected systems. The remote attack vector aligns with ATT&CK technique T1190 Exploit Public-Facing Application, which describes how adversaries target vulnerabilities in externally accessible applications to gain unauthorized access to systems. The fact that the vendor was contacted early in the disclosure process but did not respond suggests a potential lack of coordinated vulnerability disclosure practices or delayed remediation efforts that leaves users exposed to active threats.
The operational impact of this vulnerability extends beyond simple remote code execution, as it provides attackers with the ability to manipulate the router's core functionality and potentially escalate privileges within the device's operating system. Stack-based buffer overflows in web application handlers like R7WebsSecurityHandler can lead to complete system compromise, allowing unauthorized users to gain administrative control over the router. This compromise could enable attackers to redirect network traffic, install malicious firmware, or use the device as a pivot point for attacking other systems within the local network. The exploitation of this vulnerability could result in persistent access to the network, making it a valuable target for advanced persistent threat actors. Network administrators face significant risk as compromised routers can serve as entry points for broader network infiltration, potentially leading to data breaches or disruption of network services. The vulnerability's presence in a widely deployed consumer-grade router model increases the potential attack surface significantly, as many users may not be aware of the security risks or may not regularly update their firmware.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Tenda if available, though the vendor's lack of response to early disclosure suggests this may not be forthcoming. Network segmentation and firewall rules can help limit the impact if the device is compromised, while monitoring for unusual network traffic patterns or unauthorized access attempts can provide early detection of exploitation attempts. Disabling unnecessary services and remote management capabilities on the router can reduce the attack surface, and implementing network access controls can prevent unauthorized users from reaching the device's management interface. Security professionals should consider deploying intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability, while also implementing regular vulnerability assessments to identify similar issues in other network devices. The ATT&CK framework suggests that organizations should implement network monitoring and logging for suspicious activities related to web application exploitation, particularly focusing on unusual requests to management interfaces and command execution endpoints. Users should be educated about the importance of firmware updates and the risks associated with leaving network devices unpatched, as this vulnerability demonstrates how quickly public disclosure can lead to exploitation. Organizations should also consider implementing automated patch management processes to ensure that critical vulnerabilities like this one are addressed promptly across all network infrastructure components.