CVE-2019-20758 in R7000
Summary
by MITRE
NETGEAR R7000 devices before 1.0.9.42 are affected by a buffer overflow by an authenticated user.
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Analysis
by VulDB Data Team • 05/07/2025
The vulnerability identified as CVE-2019-20758 affects NETGEAR R7000 wireless routers running firmware versions prior to 1.0.9.42. This represents a critical buffer overflow flaw that can be exploited by authenticated users within the local network, potentially allowing for arbitrary code execution and system compromise. The vulnerability stems from inadequate input validation mechanisms within the device's web interface handling, specifically in the parameter processing functions that manage user-supplied data. This type of flaw falls under the Common Weakness Enumeration category CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations.
The technical implementation of this vulnerability occurs when an authenticated user submits maliciously crafted input through the web administration interface of the router. The buffer overflow manifests in the device's handling of specific parameters within HTTP requests, particularly those related to configuration settings and network management functions. When the device processes these malformed inputs without proper bounds checking, it allows an attacker to overwrite critical memory segments including return addresses and function pointers, thereby enabling arbitrary code execution. The attack vector requires local network access and valid authentication credentials, making it a privilege escalation vulnerability rather than a remote code execution flaw. This aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and T1072 which covers 'Software Deployment Tools' in the context of router management interfaces.
The operational impact of this vulnerability extends beyond simple system compromise, as authenticated attackers can potentially gain full administrative control over the affected router. This control allows for complete network traffic interception, DNS poisoning, port forwarding manipulation, and the ability to establish persistent backdoors within the local network. The router's role as a central network gateway means that successful exploitation could provide attackers with a foothold for lateral movement throughout the entire network infrastructure. Additionally, the vulnerability affects the device's ability to maintain secure network operations, as the compromised router could become a conduit for further attacks against connected devices and systems.
Mitigation strategies for CVE-2019-20758 primarily focus on firmware updates and network segmentation. The most effective solution involves upgrading the affected NETGEAR R7000 devices to firmware version 1.0.9.42 or later, which includes proper bounds checking and input validation mechanisms. Network administrators should also implement strict access controls for router management interfaces, limiting administrative access to trusted IP addresses and enforcing strong authentication mechanisms including multi-factor authentication. Additional protective measures include network monitoring for unusual traffic patterns, implementing intrusion detection systems that can identify malformed HTTP requests, and conducting regular vulnerability assessments of network infrastructure. The vulnerability demonstrates the importance of secure coding practices and the need for proper input validation in network device firmware, particularly in administrative interfaces where authenticated users can potentially exploit memory corruption flaws.