CVE-2017-6862 in WNR2000
Summary
by MITRE
NETGEAR WNR2000v3 devices before 1.1.2.14, WNR2000v4 devices before 1.0.0.66, and WNR2000v5 devices before 1.0.0.42 allow authentication bypass and remote code execution via a buffer overflow that uses a parameter in the administration webapp. The NETGEAR ID is PSV-2016-0261.
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Analysis
by VulDB Data Team • 09/09/2024
The vulnerability identified as CVE-2017-6862 represents a critical authentication bypass flaw affecting NETGEAR WNR2000 series wireless routers across multiple firmware versions. This vulnerability resides within the administration web application of affected devices and enables attackers to achieve unauthorized access and execute arbitrary code remotely. The flaw specifically manifests as a buffer overflow condition that occurs when processing a particular parameter within the web application interface, allowing malicious actors to circumvent the device's authentication mechanisms entirely.
The technical implementation of this vulnerability follows a classic buffer overflow exploit pattern where insufficient input validation permits attackers to overwrite adjacent memory locations within the web application's execution context. This memory corruption enables attackers to manipulate program execution flow and inject malicious code directly into the router's operating system. The vulnerability affects specific device models including WNR2000v3, WNR2000v4, and WNR2000v5, with firmware versions prior to the mentioned patches. According to the NETGEAR security advisory PSV-2016-0261, this issue stems from improper bounds checking in the web application's parameter handling routines.
The operational impact of this vulnerability is severe and multifaceted, as it provides complete remote control over affected devices without requiring legitimate credentials. Once exploited, attackers can gain full administrative access to the router, enabling them to modify network configurations, redirect traffic, install malware, or establish persistent backdoors. The vulnerability's remote exploitability means that attackers can target these devices from outside the local network, making it particularly dangerous for home and small office users who may not be aware of their router's exposure to the internet. This flaw directly maps to CWE-121, which describes unsafe use of stack-based buffer, and aligns with ATT&CK technique T1059 for remote code execution through network services.
Mitigation strategies for CVE-2017-6862 primarily focus on firmware updates from NETGEAR, which address the buffer overflow condition by implementing proper input validation and bounds checking mechanisms. Organizations and individuals should immediately upgrade to the patched firmware versions mentioned in the advisory, specifically versions 1.1.2.14 for WNR2000v3, 1.0.0.66 for WNR2000v4, and 1.0.0.42 for WNR2000v5 devices. Network administrators should also implement additional security measures such as disabling remote administration features, restricting access through firewall rules, and monitoring network traffic for suspicious activity. The vulnerability demonstrates the importance of proper input validation in web applications and highlights the critical need for regular firmware updates to address known security flaws in network infrastructure devices.