CVE-2018-21198 in D6100
Summary
by MITRE
Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D6100 before 1.0.0.57, R7800 before 1.2.0.44, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.92, WNDR4300 before 1.0.2.94, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.62.
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Analysis
by VulDB Data Team • 06/03/2024
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 specified patches. The vulnerability is classified as a stack-based buffer overflow under CWE-121, which occurs when a program writes data beyond the bounds of a fixed-length stack buffer, potentially leading to arbitrary code execution. The affected devices include popular models such as the D6100, R7800, R9000, and various WNDR series routers, all of which are susceptible due to improper input validation in their web management interfaces.
The technical flaw manifests when an authenticated user submits malicious input to specific web interface parameters, allowing an attacker to overflow a stack buffer and potentially overwrite adjacent memory locations including return addresses and function pointers. This type of vulnerability falls under the ATT&CK technique T1210 - Exploitation of Remote Services, specifically targeting the web management interfaces of network devices. The authentication requirement means that an attacker must first obtain valid credentials to exploit this vulnerability, which could be achieved through credential stuffing, phishing attacks, or other social engineering techniques that are commonly employed in network device compromise scenarios.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially enable full system compromise of affected routers. An authenticated attacker could leverage this buffer overflow to execute arbitrary code with the privileges of the web server process, which typically runs with elevated permissions on network devices. This could lead to complete network compromise, enabling attackers to redirect traffic, establish backdoors, or use the compromised device as a pivot point for attacking other systems within the network. The vulnerability affects devices that are widely deployed in both residential and enterprise environments, making the potential attack surface significant. The specific firmware versions mentioned indicate that this vulnerability has existed for an extended period, suggesting that many devices in the field remain unpatched and vulnerable to exploitation.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to address the specific buffer overflow conditions present in the affected models. Network administrators should also implement network segmentation to limit the potential impact of a compromised device, along with monitoring for unusual traffic patterns or unauthorized access attempts to router management interfaces. Additional security measures include enforcing strong authentication practices, implementing multi-factor authentication where possible, and regularly auditing network device configurations. Organizations should also consider deploying intrusion detection systems to monitor for exploitation attempts targeting known vulnerabilities in network infrastructure devices. The vulnerability demonstrates the importance of maintaining current firmware versions and implementing robust security practices for network infrastructure components that are often overlooked in traditional cybersecurity defenses.