CVE-2021-45564 in RBK752
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects RBK752 before 3.2.16.6, RBR750 before 3.2.16.6, RBS750 before 3.2.16.6, RBK852 before 3.2.16.6, RBR850 before 3.2.16.6, and RBS850 before 3.2.16.6.
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Analysis
by VulDB Data Team • 12/28/2021
The vulnerability CVE-2021-45564 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This security weakness allows authenticated attackers to execute arbitrary commands on affected devices, potentially leading to complete system compromise. The vulnerability specifically impacts firmware versions prior to 3.2.16.6, indicating that manufacturers released patches to address this issue. The flaw exists within the web-based management interface of these devices, where input validation mechanisms fail to properly sanitize user-supplied data before processing. This authentication requirement means that an attacker must first establish valid credentials to exploit the vulnerability, typically through legitimate administrative access or credential compromise.
The technical nature of this command injection vulnerability aligns with CWE-77 and CWE-89, which categorize command injection flaws as critical security weaknesses in software applications. The flaw operates by allowing malicious input to be interpreted and executed as shell commands within the device's operating system. When an authenticated user submits crafted input through the web interface, the system fails to properly validate or escape the input before passing it to underlying system commands. This creates an opportunity for attackers to inject malicious shell commands that execute with the privileges of the web server process, typically running with administrative privileges on the device. The impact extends beyond simple command execution to potentially enable full system compromise, data exfiltration, and persistent backdoor installation.
The operational impact of this vulnerability presents significant risks to network security and device integrity. An authenticated attacker with access to the device's web interface can potentially gain complete control over the router's functionality, including the ability to modify network configurations, redirect traffic, disable security features, and establish persistent access points. The vulnerability affects enterprise and residential networks alike, as these routers often serve as the primary gateway between internal networks and external internet access. Attackers could leverage this flaw to perform man-in-the-middle attacks, redirect DNS queries, or establish command and control channels for further network infiltration. The presence of multiple affected models suggests a widespread vulnerability that could impact numerous network environments, particularly in scenarios where default credentials remain unchanged or where administrative accounts are compromised through social engineering or credential theft.
Mitigation strategies for CVE-2021-45564 should prioritize immediate firmware updates to versions 3.2.16.6 or later, which contain the necessary patches to address the command injection vulnerability. Network administrators should implement strict access controls and authentication measures, including multi-factor authentication for administrative interfaces, to reduce the likelihood of unauthorized access. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar issues across network infrastructure. The ATT&CK framework categorizes this type of vulnerability under T1059.001 for command and scripting interpreter, highlighting the potential for lateral movement and persistent access once initial compromise occurs. Additional defensive measures include network segmentation to limit the impact of successful exploitation, implementation of intrusion detection systems to monitor for suspicious command execution patterns, and regular credential rotation to minimize the window of opportunity for attackers. Organizations should also consider network monitoring solutions that can detect anomalous traffic patterns or command execution attempts that may indicate exploitation attempts against these vulnerable devices.