CVE-2016-10174

What Is NETGEAR WNR2000v5?

The NETGEAR WNR2000v5 is a widely deployed home/SMB wireless router — part of NETGEAR's N300 Wi-Fi router line. It provides internet routing, NAT, and 802.11n wireless access for home users and small businesses. Like most consumer routers, the WNR2000v5 is managed via a web-based admin interface served by an embedded HTTP server (httpd). The WNR2000v5 was sold in large volumes and is still in active deployment, making vulnerabilities in its firmware exploitable against a significant installed base of aging, rarely-updated devices.

Consumer home routers are among the most exploited device categories in the internet threat landscape: they are always-on, rarely patched, often internet-exposed (management interfaces accessible from the WAN side), have root-level access to all network traffic, and their compromise enables DNS hijacking, traffic interception, botnet recruitment, and use as attack infrastructure.

Overview

CVE-2016-10174 is a classic buffer overflow vulnerability in the NETGEAR WNR2000v5 router's embedded web server that allows an unauthenticated remote attacker to execute arbitrary code with root privileges. The vulnerability occurs when the router's httpd processes a specially crafted request containing an oversized timestamp parameter — the embedded HTTP server copies this parameter into a fixed-size stack buffer without length validation, overflowing the buffer and enabling stack-based code execution. CISA added CVE-2016-10174 to the KEV catalog in March 2022, reflecting its sustained use in botnet recruitment and attack campaigns.

Affected Versions

Check NETGEAR's support portal for the patched firmware version for the WNR2000v5. Some older WNR2000v5 hardware revisions may no longer receive firmware updates.

Technical Details

Root Cause: Stack Buffer Overflow in httpd Timestamp Parameter

CVE-2016-10174 is a classic stack buffer overflow (CWE-120) in the NETGEAR WNR2000v5's embedded web server. The router's admin web interface includes endpoints that process timestamp parameters as part of certain HTTP request flows. The httpd binary copies this parameter value into a fixed-size stack buffer (e.g., char buf[256]) using an unsafe string copy operation (strcpy, strncpy with insufficient size) without checking the input length against the buffer's bounds.

Exploitation path:

1. Attacker sends a crafted HTTP request — a request to the WNR2000v5 web management interface (port 80) containing a timestamp parameter with a payload longer than the fixed buffer size
2. httpd copies the oversized parameter — the parameter is copied into the stack buffer without bounds checking
3. Stack overflow — the excess data overwrites the saved return address on the stack
4. Control flow hijack — when the function returns, execution redirects to attacker-controlled code
5. RCE as root — httpd runs as root on the WNR2000v5; code execution is immediately at the highest privilege level

No authentication required: The vulnerable parameter is processed before authentication checks, allowing unauthenticated exploitation from any system that can reach the router's HTTP management interface (TCP port 80).

Attack Surface: Internet-Facing Management

The NETGEAR WNR2000v5's management interface on port 80 is often accessible from the internet if:

• Remote management is enabled (default off, but sometimes enabled by users or ISPs)
• The router is deployed with the WAN port exposed to management traffic

Even with remote management disabled, LAN-side access (from within the local network) and CSRF-based attacks (via a malicious web page visited by a LAN user) can exploit the vulnerability.

Attack Characteristics

Discovery

Disclosed by security researcher Pedro Ribeiro in December 2016 alongside related NETGEAR router vulnerabilities; the NETGEAR WNR2000v5 research was part of a broader investigation into NETGEAR consumer router security (which also produced CVE-2016-6277).

Exploitation Context

• IoT botnet recruitment: The WNR2000v5 buffer overflow enables mass automated compromise of vulnerable routers for botnet recruitment; Mirai successor botnets incorporated CVE-2016-10174 alongside other router vulnerabilities to recruit IoT devices for DDoS campaigns and proxy infrastructure
• Long exploitation tail: Consumer router firmware updates are rarely applied; WNR2000v5 devices purchased in 2014-2016 are still in service at many homes and small businesses running original firmware; the long exploitation tail makes CVE-2016-10174 a persistent scanning and exploitation target
• DNS hijacking attacks: Compromised WNR2000v5 routers are used for DNS hijacking — modifying the router's DNS server settings to redirect users to phishing pages for banking, social media, and other services; root access to the router enables modifying all DNS configuration
• Traffic interception capability: A compromised router at a home or small office intercepts all unencrypted traffic from all devices on that network segment — browsing history, HTTP credentials, unencrypted email — providing persistent network surveillance
• CISA KEV (2022): Added March 25, 2022 based on confirmed active exploitation in botnet campaigns

Remediation

1. Apply NETGEAR firmware update — download and install the latest WNR2000v5 firmware from NETGEAR's support site. Verify the firmware version in the router admin panel after updating.

2. Disable remote management — ensure the WNR2000v5 web management interface is not accessible from the internet (WAN side): Admin → Remote Management → Disable. This is the most important immediate mitigation if patching is delayed.

3. Replace end-of-support devices — if NETGEAR has discontinued firmware updates for your WNR2000v5 hardware revision, replace the device with a currently supported router that receives active security patches.

4. Change router admin credentials — set a strong, unique password for the router admin interface to prevent LAN-side exploitation via default credentials.

5. Monitor for DNS hijacking — regularly check the router's DNS server settings match your ISP-assigned or chosen DNS servers; unexpected changes to DNS configuration are a sign of compromise.

6. Monitor network for router anomalies — check connected devices list and traffic patterns; unusual outbound connections from the router's management interface may indicate exploitation.