CVE-2022-29327 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 urladd parameter in /goform/websURLFilterAddDel.
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Analysis
by VulDB Data Team • 05/12/2022
The vulnerability identified as CVE-2022-29327 affects D-Link DIR-816 A2 routers running firmware version 1.10CNB04 and potentially other variants within the same product line. This issue manifests as a stack overflow condition that occurs when processing the urladd parameter within the /goform/websURLFilterAddDel endpoint. The affected device is a consumer-grade wireless router that serves as a network gateway, making it a critical target for attackers seeking to compromise home and small office networks. The vulnerability exists in the web-based management interface of the device, which allows remote attackers to execute arbitrary code through crafted input parameters.
The technical flaw stems from improper input validation and handling within the router's web server component. When the urladd parameter is processed without adequate bounds checking or sanitization, it allows an attacker to overflow the stack buffer allocated for storing this parameter value. This stack overflow condition can be exploited to overwrite adjacent memory locations, potentially leading to arbitrary code execution with the privileges of the web server process. The vulnerability is classified as a classic buffer overflow issue that falls under CWE-121 Stack-based Buffer Overflow, where insufficient bounds checking allows data to be written beyond the allocated buffer space. The attack vector is remote and requires no authentication, making it particularly dangerous as it can be exploited by anyone with network access to the device.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with persistent access to the compromised network infrastructure. Successful exploitation can enable attackers to modify firewall rules, redirect traffic, install malware, or establish backdoors for continued access. The router serves as a central point in many networks, meaning that compromise of this device can lead to broader network infiltration and lateral movement. Additionally, since the vulnerability affects the web management interface, attackers can potentially gain administrative control over the device, allowing them to modify network settings, disable security features, or create persistent access points. This aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where attackers can execute commands on compromised systems. The vulnerability also represents a significant risk to network confidentiality and integrity, as attackers can potentially monitor network traffic or modify data in transit.
Mitigation strategies for this vulnerability should include immediate firmware updates from D-Link to address the stack overflow condition. Organizations and individuals should ensure their routers are running the latest firmware versions that contain patches for this specific issue. Network segmentation and firewall rules can provide additional protection by limiting access to the router management interface to trusted networks only. Implementing network monitoring to detect unusual traffic patterns or unauthorized access attempts can help identify exploitation attempts. Regular security audits of network devices should include checking for outdated firmware versions and known vulnerabilities. The vulnerability demonstrates the importance of proper input validation and bounds checking in embedded web applications, which should be addressed through secure coding practices and regular security testing of network infrastructure devices. Given the remote exploitability and lack of authentication requirements, immediate remediation is critical to prevent unauthorized access to affected networks.