CVE-2022-29324 in DIR-816 A2
Summary
by MITRE • 05/10/2022
D-Link DIR-816 A2_v1.10CNB04 was discovered to contain a stack overflow via the proto parameter in /goform/form2IPQoSTcAdd.
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Analysis
by VulDB Data Team • 05/12/2022
The vulnerability identified as CVE-2022-29324 affects D-Link DIR-816 A2 routers running firmware version 1.10CNB04 and potentially other affected models. This issue manifests as a stack buffer overflow condition within the router's web interface handling mechanism, specifically in the /goform/form2IPQoSTcAdd endpoint. The vulnerability occurs when processing the proto parameter, which is part of the Quality of Service configuration form for IP traffic classification and prioritization. The stack overflow represents a critical security weakness that can be exploited by remote attackers to gain unauthorized control over the affected device.
The technical flaw stems from inadequate input validation and bounds checking within the router's firmware implementation. When a malicious user submits a specially crafted request containing an overly long proto parameter value to the /goform/form2IPQoSTcAdd endpoint, the device fails to properly validate the input length before copying it into a fixed-size stack buffer. This classic buffer overflow vulnerability allows an attacker to overwrite adjacent memory locations including return addresses and control data structures. The CWE-121 category applies here as this represents a stack-based buffer overflow where insufficient bounds checking permits memory corruption. The vulnerability is particularly dangerous because it can be triggered through unauthenticated web requests, making it accessible to anyone with network connectivity to the affected router.
The operational impact of this vulnerability extends beyond simple denial of service scenarios. An attacker who successfully exploits this stack overflow could potentially execute arbitrary code on the affected router with the privileges of the web server process. This could lead to complete system compromise, allowing unauthorized access to the network, modification of routing tables, interception of network traffic, or even the installation of persistent backdoors. The attack surface is particularly concerning given that many users operate these routers in home or small business environments without regular firmware updates, making them vulnerable targets. According to ATT&CK framework technique T1071.004, this vulnerability enables network protocol manipulation and could facilitate lateral movement within compromised networks. The vulnerability affects the router's core functionality and can result in complete loss of network connectivity for legitimate users while providing attackers with a persistent foothold in the network infrastructure.
Mitigation strategies for CVE-2022-29324 should prioritize immediate firmware updates from D-Link, as the vendor has released patches addressing this specific vulnerability. Network administrators should implement network segmentation and access controls to limit exposure of these devices to untrusted networks. Additional defensive measures include disabling unnecessary web management interfaces, implementing firewall rules to restrict access to the router's administrative ports, and monitoring network traffic for suspicious activity patterns. Regular vulnerability scanning and asset inventory management should be maintained to identify and remediate similar issues across the network infrastructure. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly those handling user-provided data through web interfaces. Organizations should also consider implementing intrusion detection systems to monitor for exploitation attempts targeting known vulnerabilities in network infrastructure devices.