CVE-2019-20764 in R7800
Summary
by MITRE
NETGEAR R7800 devices before 1.0.2.52 are affected by a stack-based buffer overflow by an authenticated user.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 05/31/2024
The vulnerability identified as CVE-2019-20764 affects NETGEAR R7800 wireless routers running firmware versions prior to 1.0.2.52, representing a critical stack-based buffer overflow flaw that can be exploited by authenticated attackers. This issue resides within the device's web management interface and stems from improper input validation in the handling of user-supplied data. The vulnerability manifests when an authenticated user submits specially crafted data to the affected web application, leading to a buffer overflow condition that can potentially allow arbitrary code execution on the device. The stack-based nature of this vulnerability means that the overflow occurs in the program's stack memory space, which can result in unpredictable behavior including application crashes, system instability, or more severe consequences depending on the exploitation method employed.
The technical implementation of this vulnerability involves the web server component of the router's firmware failing to properly validate the length of input data provided through web forms or API endpoints. When an authenticated user sends data exceeding the allocated buffer size, the excess data overflows into adjacent memory locations, potentially corrupting the stack frame and execution flow. This condition creates opportunities for attackers to manipulate the program's execution path, potentially leading to privilege escalation or complete system compromise. The vulnerability's classification aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows data to overwrite adjacent stack memory locations, and may also map to CWE-787 for out-of-bounds writes to memory. The attack surface is specifically limited to authenticated users who can access the device's web interface, typically requiring valid administrative credentials or user accounts with sufficient privileges.
The operational impact of CVE-2019-20764 extends beyond simple denial of service conditions, as it represents a potential gateway for more sophisticated attacks within network environments. An attacker who successfully exploits this vulnerability could gain unauthorized access to the router's operating system, potentially enabling them to modify network configurations, intercept traffic, or establish persistent access points within the network. The device's role as a central networking hub makes it an attractive target for attackers seeking to establish footholds for broader network infiltration, particularly in enterprise environments where these devices often serve as primary gateways between internal networks and external internet connections. This vulnerability also creates potential for lateral movement attacks, as compromised routers can serve as launching points for attacks against other networked devices, aligning with ATT&CK technique T1046 for network service scanning and T1071 for application layer protocol usage. The impact is particularly concerning given that many organizations may not regularly update their networking equipment, leaving these devices vulnerable for extended periods.
Mitigation strategies for CVE-2019-20764 primarily focus on firmware updates and access control measures to prevent exploitation. The most effective immediate solution involves upgrading the affected NETGEAR R7800 devices to firmware version 1.0.2.52 or later, which includes patches addressing the buffer overflow condition through proper input validation and bounds checking. Network administrators should implement strict access controls for router management interfaces, limiting access to authorized personnel only and ensuring strong authentication mechanisms are in place. Additional protective measures include network segmentation to isolate critical infrastructure from less secure network segments, implementing intrusion detection systems to monitor for unusual activity patterns, and conducting regular vulnerability assessments to identify potentially unpatched devices. The implementation of network access control lists and disabling unnecessary services on the router can further reduce the attack surface. Organizations should also establish robust patch management procedures to ensure timely deployment of security updates across all network equipment, as this vulnerability demonstrates the importance of maintaining current firmware versions to protect against known security flaws. Regular security audits of network infrastructure can help identify devices running outdated firmware that may be susceptible to similar vulnerabilities, ensuring comprehensive protection across the entire network environment.