CVE-2025-4140 in EX6120
Summary
by MITRE • 05/01/2025
A vulnerability, which was classified as critical, has been found in Netgear EX6120 1.0.3.94. Affected by this issue is the function sub_30394. The manipulation of the argument host leads to buffer overflow. The attack may be launched remotely. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 05/01/2025
This critical vulnerability in Netgear EX6120 firmware version 1.0.3.94 represents a significant security risk that stems from improper input validation within the sub_30394 function. The buffer overflow occurs when processing the host argument, creating an exploitable condition that allows remote attackers to execute arbitrary code on affected devices. This type of vulnerability falls under CWE-121, which describes buffer overflow conditions where data written to a buffer exceeds its allocated size, and aligns with ATT&CK technique T1203 for exploitation of remote services. The flaw exists in the device's network communication handling, specifically in how it processes host parameters, making it particularly dangerous for network infrastructure devices.
The remote exploitation capability of this vulnerability means that attackers can trigger the buffer overflow without requiring physical access to the device, potentially allowing them to gain unauthorized control over the network gateway. This presents a severe risk to network security as the EX6120 serves as a wireless access point and router, making it a prime target for attackers seeking to establish persistent access to corporate or home networks. The lack of vendor response to early disclosure attempts compounds the severity of this issue, leaving users without official patches or mitigation guidance for an extended period.
The operational impact of this vulnerability extends beyond simple remote code execution, as successful exploitation could enable attackers to modify network configurations, redirect traffic, or establish backdoors for continued access. Network administrators face significant challenges in identifying affected devices since the vulnerability exists in the firmware level, making detection difficult without specialized network monitoring tools. Organizations using these devices should consider implementing network segmentation and monitoring to detect potential exploitation attempts, as the buffer overflow could be leveraged to escalate privileges and access sensitive network resources.
Mitigation strategies should include immediate firmware updates from Netgear if available, though the vendor's lack of response suggests this may not be forthcoming. Network administrators should implement strict firewall rules to limit access to affected devices and consider disabling unnecessary services that might expose the vulnerable function. Additionally, monitoring for unusual network traffic patterns or attempts to communicate with the affected device's network interfaces could help detect exploitation attempts. This vulnerability demonstrates the critical importance of maintaining up-to-date firmware and the risks associated with vendor inaction in security disclosure processes, as highlighted in industry best practices for vulnerability management and incident response protocols.