CVE-2018-21144 in DM200
Summary
by MITRE
Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects DM200 before 1.0.0.52, R7500 before 1.0.0.122, R7800 before 1.0.2.42, R8900 before 1.0.3.10, R9000 before 1.0.3.16, 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 stems 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 more data to a buffer located on the stack than the buffer can accommodate, leading to memory corruption that can be exploited by malicious actors. This particular flaw allows an authenticated attacker with access to the device's web interface to manipulate memory layout and potentially execute arbitrary code on the affected systems.
The technical implementation of this vulnerability involves the exploitation of a buffer overflow condition in the web server component of the affected NETGEAR devices. When an authenticated user submits malicious input through specific web forms or parameters within the administration interface, the system fails to properly validate the input length before copying it into a fixed-size stack buffer. This allows the attacker to overwrite adjacent memory locations including return addresses and control registers, potentially enabling privilege escalation or remote code execution. The vulnerability is particularly concerning because it requires only authentication credentials, which can often be obtained through social engineering or other means, making the attack surface significantly broader than typical unauthenticated vulnerabilities.
The operational impact of CVE-2018-21144 extends beyond simple code execution, as it can provide attackers with persistent access to the network infrastructure. Once exploited, the vulnerability allows attackers to gain control over the affected routers, potentially enabling them to redirect traffic, implement man-in-the-middle attacks, or establish persistent backdoors within the network. The affected device models span multiple generations of NETGEAR's consumer and small business networking equipment, creating widespread exposure across various network environments. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter, as the exploitation can lead to command execution on the device, and T1078 Valid Accounts, since the attack requires only legitimate authentication credentials. The attack chain typically involves initial access through valid credentials followed by exploitation of the buffer overflow to escalate privileges and establish persistent access.
Mitigation strategies for this vulnerability require immediate firmware updates from NETGEAR, as the manufacturer has released patched versions addressing the buffer overflow condition. Network administrators should prioritize updating all affected devices to their latest secure firmware versions, particularly focusing on the specified model ranges and firmware versions. Additionally, implementing network segmentation and monitoring for unusual traffic patterns can help detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and memory management in embedded systems, highlighting the need for robust software development practices in network infrastructure devices. Organizations should also consider implementing network access controls to limit administrative access to these devices, reducing the attack surface for authenticated exploits. Regular vulnerability assessments and penetration testing of network infrastructure can help identify similar flaws in other networked devices and systems, ensuring comprehensive security coverage across all network endpoints.