CVE-2023-41228 in DIR-3040
Summary
by MITRE • 05/03/2024
D-Link DIR-3040 prog.cgi SetUsersSettings Stack-Based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DIR-3040 routers. Authentication is required to exploit this vulnerability.
The specific flaw exists within the prog.cgi binary, which handles HNAP requests made to the lighttpd webserver listening on TCP ports 80 and 443. The issue results from the lack of proper validation of a user-supplied string before copying it to a fixed-size stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-21654.
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Analysis
by VulDB Data Team • 05/15/2025
The CVE-2023-41228 vulnerability represents a critical stack-based buffer overflow in the D-Link DIR-3040 router's prog.cgi component, which operates as part of the lighttpd webserver infrastructure. This vulnerability resides within the HNAP (Home Network Access Protocol) request handling mechanism, making it particularly dangerous as it can be exploited through the router's web interface that listens on standard TCP ports 80 and 443. The flaw specifically manifests in the prog.cgi binary where insufficient input validation occurs before copying user-supplied data into a fixed-size stack buffer, creating an exploitable condition that can be leveraged by remote attackers with network adjacency. The vulnerability requires authentication to exploit, meaning an attacker must first establish valid credentials to the router's web interface, though this does not significantly reduce the risk given that many routers ship with default credentials or have weak authentication mechanisms.
The technical exploitation of this vulnerability follows a classic stack buffer overflow pattern where the prog.cgi binary fails to properly validate the length of user-provided input before performing a copy operation into a predetermined stack buffer. This allows an attacker to overwrite adjacent stack memory, potentially including return addresses and function pointers, which can then be manipulated to redirect execution flow to malicious code. The buffer overflow occurs in a context where the code executes with root privileges, as the web server components typically run with elevated permissions to manage router configuration and network settings. This privilege escalation capability means that successful exploitation would grant the attacker complete control over the router's operations, including access to network traffic, configuration changes, and potential lateral movement within the local network. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory safety issue that has been consistently identified as a primary attack vector in numerous security assessments and penetration testing exercises.
The operational impact of this vulnerability extends beyond simple remote code execution, as it fundamentally compromises the security posture of any network relying on affected D-Link DIR-3040 devices. Network administrators face significant risk since the router serves as a gateway device that controls network access and may be configured with default credentials that are widely known and easily exploitable. The vulnerability enables attackers to establish persistent backdoors, modify network configurations, redirect traffic, or use the compromised device as a launch point for attacks against other networked systems. This represents a substantial concern for enterprise and home network security, as the router becomes a potential pivot point for broader network infiltration. The attack surface is particularly concerning because the vulnerability exists in the web server interface, which is typically accessible to network users who may not have legitimate access to the device. According to ATT&CK framework, this vulnerability maps to T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation, demonstrating how the initial exploitation can lead to more sophisticated attack vectors within the network environment.
Mitigation strategies for CVE-2023-41228 should prioritize immediate firmware updates from D-Link, as the vendor has likely released patches addressing this specific buffer overflow condition. Network segmentation and access control measures should be implemented to restrict access to the router's web interface, particularly ensuring that only authorized personnel can reach the device through network controls such as firewalls and access control lists. Regular credential rotation and enforcement of strong authentication mechanisms, including multi-factor authentication where possible, should be implemented to reduce the risk of unauthorized access. Network monitoring should be enhanced to detect unusual traffic patterns or attempts to access the router's web interface, particularly from unexpected sources. Additionally, network administrators should conduct thorough inventory checks to identify all affected D-Link DIR-3040 devices within their network infrastructure and ensure that default credentials are changed immediately upon discovery. The vulnerability also underscores the importance of implementing robust network security monitoring solutions that can detect anomalous behavior indicative of exploitation attempts, such as unusual HNAP requests or attempts to manipulate web server components. Organizations should also consider implementing network access control policies that limit the exposure of critical network infrastructure to unnecessary network adjacency, thereby reducing the attack surface for such vulnerabilities.