CVE-2019-20733 in D6400
Summary
by MITRE
Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects D6220 before 1.0.0.44, D6400 before 1.0.0.78, D7000v2 before 1.0.0.51, D8500 before 1.0.3.42, DGN2200v4 before 1.0.0.110, DGND2200Bv4 before 1.0.0.110, EX3700 before 1.0.0.70, EX3800 before 1.0.0.70, EX6000 before 1.0.0.30, EX6100 before 1.0.2.24, EX6120 before 1.0.0.40, EX6130 before 1.0.0.22, EX6150v1 before 1.0.0.42, EX6200 before 1.0.3.88, EX7000 before 1.0.0.66, R6250 before 1.0.4.26, R6300v2 before 1.0.4.28, R6400 before 1.0.1.36, R6400v2 before 1.0.2.52, R6700 before 1.0.1.46, R6900 before 1.0.1.46, R7000 before 1.0.9.28, R6900P before 1.3.1.64, R7000P before 1.3.1.64, R7100LG before 1.0.0.46, R7300DST before 1.0.0.68, R7900 before 1.0.2.10, R8000 before 1.0.4.12, R7900P before 1.3.0.10, R8000P before 1.3.0.10, R8300 before 1.0.2.122, R8500 before 1.0.2.122, WN2500RPv2 before 1.0.1.54, WNDR3400v3 before 1.0.1.22, and WNR3500Lv2 before 1.2.0.54.
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Analysis
by VulDB Data Team • 05/31/2024
This vulnerability represents a critical stack-based buffer overflow condition that affects numerous NETGEAR wireless routers and networking devices, creating significant security risks for affected networks. The flaw exists in the device's handling of input data within network communication protocols, specifically in the web server component that processes HTTP requests from remote attackers. The vulnerability is particularly dangerous because it requires no authentication to exploit, making it accessible to any attacker with network connectivity to the affected devices. According to CWE-121, this vulnerability falls under stack-based buffer overflow conditions where insufficient bounds checking allows an attacker to overwrite adjacent memory locations on the stack, potentially leading to arbitrary code execution or system crashes.
The technical implementation of this vulnerability occurs when malformed input data is processed by the affected devices' web interface, particularly in parameters related to network configuration or device management functions. Attackers can craft malicious HTTP requests that exceed the allocated buffer space, causing the stack to overflow and potentially overwrite critical program execution pointers or return addresses. This allows for complete system compromise, as demonstrated by the specific device model ranges affected including popular models such as the R6250, R7000, D8500, and EX3700 series. The vulnerability affects firmware versions prior to specific release numbers, indicating that NETGEAR has issued patches to address this issue, though many devices remain unpatched in production environments.
The operational impact of this vulnerability extends beyond simple device compromise, as it enables attackers to gain complete administrative control over affected networking equipment. This provides unauthorized access to network traffic, potential lateral movement within the network, and the ability to redirect traffic through malicious proxies or servers. The attack surface is particularly concerning given that these devices are typically deployed in residential and small business environments where network security is often minimal, making the exploitation process relatively straightforward. From an ATT&CK framework perspective, this vulnerability maps to multiple techniques including T1059 for command execution, T1021 for remote services, and T1046 for network service discovery, creating a comprehensive attack vector for network infiltration.
Mitigation strategies must focus on immediate firmware updates from NETGEAR to address the specific buffer overflow conditions, as well as network segmentation to limit access to these devices. Organizations should implement network monitoring to detect anomalous traffic patterns that may indicate exploitation attempts, particularly focusing on HTTP requests that exceed normal parameter lengths. Additionally, network administrators should disable unnecessary services and ensure that only authorized personnel have physical or remote access to these devices. The vulnerability highlights the importance of regular firmware updates and security assessments, as many of these devices remain in use with outdated firmware versions that have known security flaws. Network defenders should also consider implementing intrusion detection systems to monitor for exploitation attempts targeting these specific device models and firmware versions.