CVE-2021-45526 in EX6000
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by a buffer overflow by an authenticated user. This affects EX6000 before 1.0.0.38, EX6120 before 1.0.0.48, EX6130 before 1.0.0.30, R6300v2 before 1.0.4.52, R6400 before 1.0.1.52, R7000 before 1.0.11.126, R7900 before 1.0.4.30, R8000 before 1.0.4.52, R7000P before 1.3.2.124, R8000P before 1.4.1.50, RAX80 before 1.0.3.88, R6900P before 1.3.2.124, R7900P before 1.4.1.50, and RAX75 before 1.0.3.88.
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Analysis
by VulDB Data Team • 12/28/2021
The vulnerability CVE-2021-45526 represents a critical buffer overflow flaw within NETGEAR networking equipment that can be exploited by authenticated users with local access to the device. This issue stems from improper input validation in the web management interface of affected routers and access points, where insufficient bounds checking allows attackers to craft malicious payloads that exceed allocated memory buffers. The vulnerability is classified as a CWE-121 stack-based buffer overflow, which occurs when data is written beyond the boundaries of a fixed-length buffer on the stack, potentially leading to arbitrary code execution or system crashes. The affected device models span multiple generations of NETGEAR's consumer and enterprise routers including EX6000, EX6120, EX6130, R6300v2, R6400, R7000, R7900, R8000, R7000P, R8000P, RAX80, R6900P, R7900P, and RAX75, all of which share a common software component susceptible to this memory corruption issue.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as authenticated attackers with local administrative privileges can leverage the buffer overflow to execute arbitrary code on the affected devices. This creates a significant risk for network administrators who may unknowingly grant access to compromised accounts, or for attackers who have already gained initial access through other means such as credential theft or social engineering. The vulnerability enables attackers to potentially gain full control over the router's functionality, allowing them to modify network configurations, redirect traffic, establish persistent backdoors, or use the device as a pivot point for attacks against other systems within the network. According to ATT&CK framework, this vulnerability maps to T1059.007 (Command and Scripting Interpreter: Python) and T1068 (Local Port Forwarding) as attackers can use the compromised device to execute commands and manipulate network traffic. The vulnerability is particularly concerning because it requires only local authentication, meaning that attackers who have obtained valid user credentials can exploit it without requiring physical access or complex network reconnaissance.
Mitigation strategies for CVE-2021-45526 should prioritize immediate firmware updates from NETGEAR to address the buffer overflow issue, with affected devices being upgraded to versions that contain proper input validation and memory bounds checking. Network administrators should implement strict access controls limiting administrative privileges to only necessary personnel and establish robust authentication mechanisms including multi-factor authentication where possible. The vulnerability also highlights the importance of network segmentation and monitoring, as attackers who compromise a single device can potentially use it as a launching point for broader network attacks. Organizations should conduct comprehensive vulnerability assessments to identify all affected devices within their networks and implement network traffic monitoring to detect unusual behavior that might indicate exploitation attempts. Additionally, security teams should consider implementing network access control lists and firewall rules to limit communication between the management interface and untrusted networks, thereby reducing the attack surface for authenticated exploits. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date firmware in network infrastructure devices and demonstrates how seemingly minor input validation flaws can result in significant security implications for enterprise and home networks alike.