CVE-2022-28571 in DIR-882
Summary
by MITRE • 05/02/2022
D-link 882 DIR882A1_FW130B06 was discovered to contain a command injection vulnerability in`/usr/bin/cli.
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Analysis
by VulDB Data Team • 05/04/2022
The vulnerability identified as CVE-2022-28571 affects D-Link DIR882A1 routers running firmware version 130B06 and represents a critical command injection flaw within the device's command line interface executable. This vulnerability resides in the /usr/bin/cli binary which serves as the primary interface for executing administrative commands on the router. The flaw allows remote attackers to inject malicious commands that execute with elevated privileges, potentially compromising the entire network infrastructure. The vulnerability stems from insufficient input validation and sanitization within the cli binary, which fails to properly filter user-supplied data before incorporating it into system command executions. This weakness creates a direct pathway for attackers to bypass authentication mechanisms and gain unauthorized access to the router's underlying operating system.
The technical implementation of this command injection vulnerability follows the characteristics of CWE-77 and CWE-88, where user-controllable input is directly concatenated into command strings without proper sanitization. Attackers can exploit this by crafting malicious payloads that manipulate the cli binary's argument parsing mechanisms to execute arbitrary operating system commands. The vulnerability's exploitation typically involves sending specially crafted HTTP requests or CLI commands that trigger the vulnerable code path within the /usr/bin/cli executable. The affected firmware version indicates this is a persistent issue within the DIR882A1 product line, suggesting the flaw exists in the base firmware implementation rather than being a temporary configuration error. This makes the vulnerability particularly concerning as it affects a wide range of devices deployed in residential and small office environments where network security is often insufficiently managed.
The operational impact of CVE-2022-28571 extends beyond simple unauthorized access to encompass complete network compromise and potential data exfiltration. Once exploited, attackers can gain root access to the router's operating system, enabling them to modify network configurations, install persistent backdoors, redirect traffic, or use the compromised device as a pivot point for attacking other systems within the local network. The vulnerability's remote exploitability means attackers do not require physical access or network credentials to initiate attacks, making it particularly dangerous for unsecured home networks. This flaw aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1021.001 for remote services, as it enables attackers to execute commands remotely and establish persistent network access. The compromised router can serve as a launching point for broader attacks including DNS hijacking, man-in-the-middle attacks, or as a botnet node for distributed denial-of-service attacks against other targets.
Mitigation strategies for CVE-2022-28571 should prioritize immediate firmware updates from D-Link, as the vendor has likely released patches addressing the command injection vulnerability. Network administrators should implement strict firewall rules to limit access to the router's administrative interfaces, particularly blocking external access to management ports. The principle of least privilege should be enforced by disabling unnecessary services and ensuring only authorized personnel can access the router's configuration interface. Regular network monitoring for unusual traffic patterns or unauthorized configuration changes can help detect exploitation attempts. Organizations should also consider implementing network segmentation to limit the potential damage from a compromised device, ensuring that even if a router is breached, attackers cannot easily move laterally within the network. Additionally, network administrators should conduct regular vulnerability assessments of their network infrastructure to identify and remediate similar vulnerabilities in other network devices. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, emphasizing the need for robust security testing throughout the development lifecycle of network equipment.