CVE-2018-21150 in D7800
Summary
by MITRE
Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D7800 before 1.0.1.34, DM200 before 1.0.0.50, R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7500v2 before 1.0.3.26, R7800 before 1.0.2.42, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.64.
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Analysis
by VulDB Data Team • 06/01/2024
This vulnerability represents a critical stack-based buffer overflow flaw that affects multiple NETGEAR router models, specifically targeting devices running firmware versions prior to the listed secure releases. The issue arises from insufficient input validation within the device's web administration interface, where authenticated users can exploit a flaw in the handling of user-supplied data. The vulnerability is classified as CWE-121 Stack-based Buffer Overflow, which occurs when a program writes data beyond the boundaries of a fixed-length stack buffer, potentially allowing attackers to overwrite adjacent memory locations and execute arbitrary code. The affected devices include popular NETGEAR models such as the D7800, R6100, R7500 series, and various WNDR and WNR models, all of which are susceptible to this memory corruption vulnerability through authenticated access.
The technical exploitation of this vulnerability requires an authenticated user with access to the device's web interface, which aligns with the MITRE ATT&CK framework's privilege escalation tactics and techniques. Attackers can craft malicious input parameters that exceed the allocated buffer space, causing a stack overflow that may lead to code execution with the privileges of the web server process. This typically results in a system compromise that allows for persistent access, data exfiltration, or further network exploitation. The vulnerability is particularly concerning because it requires minimal privileges to exploit, as the attacker only needs valid login credentials for the device's administration interface. The impact extends beyond simple code execution to potentially enable attackers to modify device configurations, install malware, or establish backdoors that persist across reboots.
The operational impact of this vulnerability presents significant risks to network security infrastructure, as compromised routers can serve as entry points for broader network attacks or as pivot points for lateral movement within corporate environments. Organizations using affected NETGEAR devices face potential exposure to man-in-the-middle attacks, DNS hijacking, or complete network compromise if attackers gain access through this vulnerability. The widespread deployment of these router models across both enterprise and residential networks amplifies the potential impact, as many organizations may not have comprehensive visibility into all connected devices. Security teams must prioritize patching these devices as a matter of urgency, particularly in environments where network segmentation is not properly implemented, as the vulnerability could enable attackers to bypass traditional network security controls and gain access to sensitive internal systems. The exploitation of this vulnerability can also lead to denial of service conditions if the buffer overflow causes the device to crash or reboot unexpectedly, potentially disrupting network connectivity for extended periods.
Mitigation strategies should include immediate firmware updates to the latest secure versions provided by NETGEAR, which address the buffer overflow through proper input validation and bounds checking mechanisms. Network administrators should implement strict access controls and authentication measures, ensuring that only authorized personnel have administrative access to these devices. Additional protective measures include network segmentation to isolate critical infrastructure from potentially compromised devices, implementing intrusion detection systems to monitor for unusual administrative activity, and conducting regular vulnerability assessments to identify other potentially vulnerable network assets. The vulnerability also underscores the importance of maintaining up-to-date security patches and implementing robust device management practices, as many organizations may not have visibility into all network devices that could be affected by such flaws. Organizations should also consider implementing network monitoring solutions that can detect anomalous behavior indicative of device compromise, such as unexpected network traffic patterns or unauthorized configuration changes that might result from exploitation of this vulnerability.