CVE-2021-45601 in CBR40
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects CBR40 before 2.5.0.24, CBR750 before 4.6.3.6, RBK852 before 3.2.17.12, RBR850 before 3.2.17.12, and RBS850 before 3.2.17.12.
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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 authenticated attackers to execute arbitrary commands on affected devices. The vulnerability affects multiple models within the CBR40, CBR750, RBK852, RBR850, and RBS850 device families, with specific versions prior to 2.5.0.24, 4.6.3.6, 3.2.17.12, 3.2.17.12, and 3.2.17.12 respectively. The flaw resides in the device management interface where user input is not properly sanitized before being processed, creating an opportunity for malicious command execution. This type of vulnerability falls under CWE-77 which specifically addresses command injection vulnerabilities, where untrusted data is incorporated into system commands without proper validation or escaping mechanisms. The impact is particularly severe because the vulnerability requires only authentication, meaning that an attacker who has gained access to the device management interface can escalate their privileges to full system control.
The operational implications of this vulnerability extend beyond simple command execution, as it provides attackers with complete control over affected networking equipment. Once exploited, attackers can modify device configurations, redirect traffic, install malicious firmware, or use the compromised device as a pivot point for further attacks within the network. The affected devices operate as network infrastructure components that often serve as gateways between internal networks and external internet access, making them prime targets for attackers seeking persistent access or lateral movement opportunities. From an attack perspective, this vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as the authenticated user can leverage the injection flaw to gain elevated system privileges. The vulnerability's presence in firmware versions suggests that it may have been introduced during development phases where input validation was insufficiently implemented or tested, particularly in web-based administrative interfaces that handle user-supplied parameters.
Network administrators face significant challenges in addressing this vulnerability due to the widespread deployment of affected NETGEAR devices across enterprise and residential networks. The remediation process requires immediate firmware updates from NETGEAR, which may not be immediately available or could introduce compatibility issues with existing network configurations. Organizations should implement network segmentation to limit access to administrative interfaces and consider disabling unnecessary management services until updates are deployed. The vulnerability demonstrates the importance of secure coding practices, particularly in embedded systems where resource constraints may lead to insufficient input validation. Security monitoring should focus on detecting unusual administrative activity patterns, as attackers may attempt to use the command injection to establish persistence or exfiltrate data from the network. Additionally, organizations should perform thorough vulnerability assessments to identify all instances of affected devices within their infrastructure and implement multi-factor authentication for administrative access to reduce the risk of exploitation. The incident highlights the critical need for regular firmware updates and security testing of network infrastructure components to prevent similar vulnerabilities from being exploited in production environments.