CVE-2018-21113 in D6100
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects D6100 before 1.0.0.58, D7800 before 1.0.1.42, R6100 before 1.0.1.28, R7500 before 1.0.0.130, R7500v2 before 1.0.3.36, R7800 before 1.0.2.52, R8900 before 1.0.4.12, R9000 before 1.0.4.12, WNDR3700v4 before 1.0.2.102, WNDR4300 before 1.0.2.104, WNDR4300v2 before 1.0.0.56, and WNDR4500v3 before 1.0.0.56.
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Analysis
by VulDB Data Team • 06/01/2024
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows unauthenticated attackers to execute arbitrary commands on affected devices. The vulnerability stems from improper input validation within the web interface handling of specific router models, creating an avenue for remote code execution without requiring any authentication credentials. The affected devices span multiple product lines including the D6100, D7800, R6100, R7500, R7500v2, R7800, R8900, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, and WNDR4500v3 models. The vulnerability exists in firmware versions prior to the specified patches, indicating that these devices were shipped with insufficient sanitization of user-supplied input parameters. The attack vector is particularly concerning as it operates over the web interface, making it accessible to anyone who can reach the device's IP address without requiring any prior authentication or privileged access. This aligns with CWE-77 and CWE-94 categories which specifically address command injection vulnerabilities where attacker-controlled data is executed as commands. The operational impact of this vulnerability extends beyond simple remote code execution to potentially enable full device compromise, allowing attackers to modify network configurations, establish persistent backdoors, or redirect traffic through the compromised router. The vulnerability enables attackers to perform actions such as changing administrator passwords, disabling security features, or even installing malicious firmware. This represents a significant risk to network security as compromised routers can serve as entry points for lateral movement within corporate networks or as amplification points for further attacks. The vulnerability also maps to ATT&CK technique T1059.001 which describes command and scripting interpreter usage, specifically targeting the execution of commands through web interfaces. Organizations should immediately implement network segmentation to isolate affected devices from critical network segments, disable unnecessary web interface access where possible, and deploy network monitoring to detect suspicious command execution patterns. The most effective mitigation strategy involves updating all affected devices to their latest firmware versions, which contain proper input validation and sanitization mechanisms. Network administrators should also consider implementing firewall rules that restrict access to device management interfaces to trusted IP addresses only, while ensuring that automatic firmware update mechanisms are enabled to maintain ongoing protection against similar vulnerabilities. The broader implications of this vulnerability highlight the importance of secure coding practices in embedded networking devices and the need for regular security assessments of firmware components. This vulnerability demonstrates how insufficient input validation in web interfaces can create severe security implications, particularly in network infrastructure devices that are often left exposed to external networks without proper access controls. The risk assessment should include consideration of the device's role in the network architecture and potential impact if compromised, as these routers typically serve as gateways and may contain sensitive network configuration data that could be leveraged for more extensive attacks.