CVE-2019-20737 in D6220
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 1.0.0.106, DGND2200Bv4 before 1.0.0.106, 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, R6400 before 1.0.1.42, R6700 before 1.0.1.46, R6700v3 before 1.0.2.52, R6900 before 1.0.1.46, R7000 before 1.0.9.28, 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 1.0.1.24, 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 affecting numerous NETGEAR router models, with the flaw residing in the device's handling of network requests. The vulnerability allows unauthenticated attackers to exploit the buffer overflow through specially crafted input data, potentially leading to arbitrary code execution or system compromise. The affected devices span multiple product lines including routers, wireless access points, and networking equipment, with specific versions identified in the affected software releases. The stack-based nature of the vulnerability indicates that attacker-controlled data is written beyond the bounds of a fixed-length buffer allocated on the stack, creating opportunities for memory corruption and execution control. According to CWE-121, this maps directly to stack-based buffer overflow conditions where insufficient bounds checking allows data to overwrite adjacent memory locations, potentially corrupting program execution flow.
The operational impact of this vulnerability extends beyond simple denial of service, as unauthenticated remote code execution represents a severe threat to network infrastructure security. Attackers could leverage this flaw to gain full control over affected devices, potentially using them as entry points for broader network infiltration or to establish persistent backdoors. The vulnerability affects devices with firmware versions prior to specific patches, indicating that the flaw existed in multiple generations of NETGEAR networking equipment. The widespread nature of affected models suggests that this vulnerability could impact thousands of devices across various network environments, from residential to enterprise deployments. The lack of authentication requirements makes exploitation particularly dangerous as it requires no prior access credentials or network privileges.
From a security perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically the use of shell commands and scripts, as successful exploitation could enable attackers to execute arbitrary commands on compromised devices. The vulnerability also relates to T1021.001 for remote services and T1046 for network service scanning, as attackers would likely use this flaw to establish persistent access and scan network topology. The buffer overflow condition creates a potential for privilege escalation attacks, as successful exploitation could allow attackers to execute code with the privileges of the affected service or process. Network segmentation and firewall rules that typically protect internal networks from external threats become ineffective if attackers can compromise these devices, as they provide direct access to internal network resources.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR, as the vendor has released patches addressing this vulnerability in the affected versions. Network administrators should implement monitoring for unusual network traffic patterns that might indicate exploitation attempts, particularly targeting the affected device models. Access control measures including network segmentation and firewall rules should be reviewed to limit exposure of these devices to untrusted networks. The vulnerability demonstrates the importance of secure coding practices and input validation in network infrastructure devices, as the flaw stems from inadequate bounds checking in the device's software implementation. Organizations should conduct comprehensive inventory audits to identify all affected devices within their network infrastructure and prioritize remediation based on risk assessment. Regular security assessments and vulnerability scanning should include checking for outdated firmware versions, as this vulnerability highlights the ongoing need for firmware maintenance and security updates in networking equipment.