CVE-2019-20699 in GS105Ev2
Summary
by MITRE
Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects GS105Ev2 before 1.6.0.4, GS105PE before 1.6.0.4, GS408EPP before 1.0.0.15, GS808E before 1.7.0.7, GS908E before 1.7.0.3, GSS108E before 1.6.0.4, and GSS108EPP before 1.0.0.15.
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Analysis
by VulDB Data Team • 05/27/2024
The vulnerability identified as CVE-2019-20699 represents a critical buffer overflow flaw affecting multiple NETGEAR network switching devices, including various models of GS105E, GS408E, GS808E, GS908E, and GSS108E series. This vulnerability stems from improper input validation within the device's web interface handling mechanism, creating a condition where an attacker can overflow a fixed-size buffer through crafted HTTP requests. The flaw exists in the authentication handling code where user-supplied input is directly processed without adequate bounds checking, allowing malicious data to overwrite adjacent memory locations. According to CWE-121, this vulnerability falls under the category of stack-based buffer overflow, where insufficient bounds checking permits an attacker to overwrite stack variables and potentially execute arbitrary code.
The technical exploitation of this vulnerability occurs through unauthenticated network access to the affected device's web management interface. An attacker can craft specially formatted HTTP requests that contain excessive input data, causing the buffer to overflow and overwrite critical memory segments including return addresses and function pointers. This memory corruption can lead to arbitrary code execution with the privileges of the web server process, typically running with elevated system privileges. The attack vector specifically targets the device's HTTP request parsing functionality, where the buffer overflow occurs in the handling of HTTP headers or form parameters. This type of vulnerability aligns with ATT&CK technique T1210, which describes exploitation of remote services through buffer overflow attacks, and represents a significant threat to network infrastructure security.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it allows attackers to gain complete control over affected network switching devices. Once exploited, attackers can manipulate network traffic flow, redirect communications, install backdoors, or use the compromised device as a pivot point for further attacks within the network. The affected devices operate at the network infrastructure level, making them particularly valuable targets for attackers seeking persistent access or network disruption. The vulnerability affects multiple device models across different generations, indicating a systemic flaw in the firmware development process rather than isolated incidents. This widespread impact means that organizations with multiple NETGEAR switches across their network infrastructure face significant risk of coordinated attacks exploiting the same vulnerability across their entire network.
Organizations should immediately implement mitigation strategies including firmware updates to the latest available versions, network segmentation to limit access to management interfaces, and deployment of intrusion detection systems to monitor for exploitation attempts. The recommended remediation involves upgrading all affected devices to firmware versions that include proper bounds checking and input validation mechanisms. Security teams should also implement network access controls restricting management interface access to trusted networks only, while monitoring for suspicious HTTP traffic patterns that may indicate exploitation attempts. According to NIST guidelines for network device security, this vulnerability requires immediate attention due to its unauthenticated nature and the potential for widespread network compromise. The vulnerability demonstrates the critical importance of input validation in embedded network devices and highlights the need for comprehensive security testing of firmware components before deployment in production environments.