CVE-2021-45623 in R7800
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects R7800 before 1.0.2.74, R9000 before 1.0.5.2, and XR500 before 2.3.2.66.
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Analysis
by VulDB Data Team • 12/28/2021
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows unauthenticated remote attackers to execute arbitrary commands on affected devices. The vulnerability impacts several popular router models including the R7800, R9000, and XR500 series, with specific version thresholds indicating the scope of affected firmware releases. The command injection vulnerability arises from insufficient input validation and sanitization within the device's web interface or API endpoints that process user-supplied data. Attackers can exploit this weakness by crafting malicious payloads that get executed within the device's command processing environment, potentially enabling full system compromise without requiring authentication credentials.
The technical implementation of this vulnerability typically involves the device improperly handling user input through web forms, API calls, or network protocols that interface with the underlying operating system. When legitimate user input is passed directly to system commands without proper sanitization, attackers can inject malicious commands that execute with the privileges of the affected service or application. This pattern aligns with CWE-77 and CWE-89 categories which classify command injection vulnerabilities and improper input validation respectively. The vulnerability's impact is particularly severe because it operates at the network level where attackers can leverage it to gain complete control over the affected networking equipment.
From an operational perspective, this vulnerability creates significant risk for network security and infrastructure integrity. An unauthenticated attacker can potentially gain root access to affected routers, enabling them to modify network configurations, redirect traffic, install malware, or establish persistent backdoors. The attack surface extends beyond simple device compromise to include potential man-in-the-middle attacks, DNS hijacking, and traffic interception capabilities that can affect entire network segments. Network administrators face the challenge of identifying affected devices across their infrastructure, as these vulnerabilities may remain undetected for extended periods due to the lack of authentication requirements for exploitation.
The remediation approach for this vulnerability requires immediate firmware updates from NETGEAR addressing the specific command injection flaws in the affected device models. Organizations should implement network segmentation and monitoring to detect potential exploitation attempts, while also considering the deployment of intrusion detection systems that can identify malicious command injection patterns. Security controls should include regular vulnerability assessments to identify other potentially affected devices, network access controls to limit exposure, and comprehensive network monitoring to detect anomalous command execution patterns. This vulnerability demonstrates the importance of secure coding practices and proper input validation in embedded systems, particularly those handling network traffic and user interfaces. The attack vector represents a classic example of how insufficient sanitization of user input can lead to complete system compromise, with implications for network security posture and incident response planning. Organizations should also consider implementing network-wide monitoring solutions that can detect unauthorized command execution attempts and maintain detailed logs of all administrative activities for forensic analysis purposes.