CVE-2018-21148 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 condition that affects multiple NETGEAR router models, specifically those listed in the affected versions. The flaw occurs within the web interface administration component of these devices, where an authenticated user can exploit a programming error that allows arbitrary code execution. The vulnerability stems from insufficient input validation in the handling of user-supplied data, particularly within the parameter processing functions that manage configuration changes through the web-based management interface. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is classified as a serious security weakness that can lead to complete system compromise.
The technical implementation of this vulnerability involves the manipulation of input parameters through the device's web administration interface, where an authenticated user can craft malicious payloads that exceed the allocated buffer space on the stack. When the device processes these malformed inputs, the excess data overflows into adjacent memory locations, potentially corrupting the program's execution flow and allowing an attacker to inject and execute arbitrary code. The exploitation requires authentication credentials, which limits the attack surface but does not eliminate the severity of the issue, as it can be leveraged by insiders or compromised users with legitimate access. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, specifically the use of web shells or command injection techniques.
The operational impact of this vulnerability is severe, as it allows an authenticated attacker to gain full control over the affected devices, potentially enabling them to modify network configurations, redirect traffic, establish persistent backdoors, or use the devices as entry points for further attacks within the network. The affected devices typically serve as primary network gateways, making them attractive targets for attackers seeking to establish persistent access or conduct man-in-the-middle attacks. Network segmentation and proper access controls become critical defensive measures, as the vulnerability can be exploited by users who already possess legitimate credentials to the device administration interface. The attack surface is particularly concerning because these are consumer-grade routers that are often deployed without proper security hardening and may be managed by users with limited security awareness.
Mitigation strategies for this vulnerability include immediate firmware updates from NETGEAR, which address the buffer overflow through proper input validation and memory boundary checking mechanisms. Organizations should also implement network monitoring to detect unusual traffic patterns that might indicate exploitation attempts, particularly around the web administration ports of these devices. Access controls should be strictly enforced, limiting administrative access to only authorized personnel and implementing multi-factor authentication where possible. Network segmentation can help contain potential compromises, and regular security audits should verify that devices are running patched firmware versions. The vulnerability highlights the importance of secure coding practices and input validation, particularly in network infrastructure devices that are accessible through web interfaces. Additionally, implementing network access controls that restrict administrative access to these devices from untrusted networks and monitoring for anomalous behavior can provide additional layers of defense against exploitation attempts.