CVE-2019-20722 in D7800
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D7800 before 1.0.1.44, DM200 before 1.0.0.58, R7500v2 before 1.0.3.38, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, RBK20 before 2.3.0.28, RBR20 before 2.3.0.28, RBS20 before 2.3.0.28, RBK50 before 2.3.0.32, RBR50 before 2.3.0.32, RBS50 before 2.3.0.32, RBS40 before 2.3.0.28, WNDR4300v2 before 1.0.0.58, WNDR4500v3 before 1.0.0.58, WNR2000v5 before 1.0.0.68, and XR500 before 2.3.2.32.
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Analysis
by VulDB Data Team • 05/31/2024
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows authenticated users to execute arbitrary commands on affected devices. The issue stems from improper input validation within the web interface authentication handling mechanism, specifically in the processing of user-supplied parameters that are subsequently passed to system commands without adequate sanitization. The vulnerability affects a wide range of NETGEAR routers and wireless access points across multiple product lines, including the D7800, R7500v2, R7800, R8900, R9000, and various RBK, RBR, and RBS series devices. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-77, which describes improper neutralization of special elements used in a command, making it a classic command injection vulnerability. The flaw enables an attacker who has already gained access to the device through legitimate authentication to escalate privileges and execute malicious commands with the same privileges as the web interface user, which typically operates with administrative privileges.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the ability to manipulate network configurations, access sensitive data, and potentially compromise the entire network infrastructure. An authenticated attacker can leverage this vulnerability to modify firewall rules, change network settings, access stored credentials, and even install malicious firmware updates. The attack surface is particularly concerning because these devices are often deployed in home and small office environments where network security is frequently inadequate, and users may not regularly update their firmware. The vulnerability exists in multiple versions of affected devices, indicating a persistent flaw in the software development lifecycle that was not properly addressed in the affected firmware releases. This allows attackers to exploit the vulnerability across a broad range of devices, increasing the potential attack surface significantly.
The technical exploitation of this vulnerability requires an authenticated user session, which means that attackers must first obtain valid credentials through social engineering, credential stuffing, or other means to gain access to the device. Once authenticated, attackers can manipulate input fields within the web interface to inject malicious commands that are then executed by the underlying operating system. The vulnerability is particularly dangerous because it allows for arbitrary code execution, which can be used to establish persistent backdoors, exfiltrate network traffic, or perform man-in-the-middle attacks against other devices on the network. From an adversarial perspective, this vulnerability aligns with ATT&CK technique T1059.001, which describes command and scripting interpreter, and T1068, which describes exploit for privilege escalation. Organizations should consider this vulnerability as part of a broader attack chain where initial access is gained through credential compromise, followed by privilege escalation through command injection to achieve full network control. The recommended mitigation strategy involves immediate firmware updates from NETGEAR to address the command injection vulnerability, along with implementing network segmentation, monitoring for suspicious command execution patterns, and ensuring that authentication credentials are properly secured and regularly rotated.