CVE-2022-31937 in N300
Summary
by MITRE • 09/23/2022
Netgear N300 wireless router wnr2000v4-V1.0.0.70 was discovered to contain a stack overflow via strcpy in uhttpd.
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Analysis
by VulDB Data Team • 05/27/2025
The vulnerability identified as CVE-2022-31937 affects Netgear N300 wireless routers with firmware version wnr2000v4-V1.0.0.70 and represents a critical stack overflow condition within the uhttpd web server component. This issue arises from improper input validation when handling user-supplied data through the strcpy function, which lacks bounds checking mechanisms. The vulnerability exists in the web interface handling code where untrusted data from HTTP requests is directly copied to a fixed-size buffer on the stack without adequate size verification.
The technical flaw manifests when an attacker sends a specially crafted HTTP request containing excessive data to the router's web interface. The strcpy function, which does not perform bounds checking, copies this oversized input directly into a stack buffer that is insufficiently sized to accommodate the incoming data. This buffer overflow condition allows an attacker to overwrite adjacent stack memory locations, potentially corrupting the program's execution flow and enabling arbitrary code execution. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which is a well-documented and highly dangerous class of vulnerability that has been extensively catalogued in the Common Weakness Enumeration database.
The operational impact of this vulnerability is severe as it provides remote attackers with the capability to completely compromise the affected Netgear routers. An attacker could execute arbitrary code with the privileges of the web server process, which typically runs with elevated permissions on the device. This compromise could enable attackers to gain full administrative control over the router, allowing them to modify network settings, intercept traffic, install malicious firmware, or use the device as a pivot point for attacking other systems within the local network. The vulnerability is particularly concerning because it affects a widely deployed consumer-grade router model, making it a prime target for mass exploitation campaigns.
Mitigation strategies for this vulnerability should include immediate firmware updates from Netgear, as the vendor has likely released patches addressing this specific buffer overflow condition. Network administrators should also implement network segmentation and access controls to limit exposure of these devices to untrusted networks. Additional protective measures include disabling unnecessary services, implementing strong authentication mechanisms, and monitoring network traffic for suspicious patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and proper buffer management practices, aligning with ATT&CK technique T1059.007 for command and script interpreter execution, as exploitation typically involves injecting malicious commands through the vulnerable web interface. Organizations should also consider implementing intrusion detection systems that can identify patterns associated with buffer overflow exploitation attempts and maintain comprehensive network monitoring to detect unauthorized access to critical network infrastructure devices.