CVE-2025-45931 in DIR-816
Summary
by MITRE • 06/30/2025
An issue D-Link DIR-816-A2 DIR-816A2_FWv1.10CNB05_R1B011D88210 allows a remote attacker to execute arbitrary code via system() function in the bin/goahead file
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Analysis
by VulDB Data Team • 07/01/2025
The vulnerability identified as CVE-2025-45931 affects D-Link DIR-816-A2 and DIR-816A2_FWv1.10CNB05_R1B011D88210 router firmware versions, representing a critical remote code execution flaw that directly impacts network security infrastructure. This vulnerability resides within the bin/goahead file, which serves as a web server component embedded in the router's firmware, making it a prime target for attackers seeking persistent access to networked environments. The issue stems from improper input validation and sanitization within the system() function, which allows malicious actors to inject and execute arbitrary commands on the affected device. This represents a classic buffer overflow vulnerability that has been classified under CWE-121, which deals with stack-based buffer overflow conditions, though the specific implementation in this case involves command injection through web interface parameters.
The technical exploitation of this vulnerability occurs through the manipulation of input parameters that are passed to the system() function within the goahead web server component. When an attacker crafts malicious input and submits it through the web interface, the system() function executes the crafted command with the privileges of the web server process, typically running with elevated permissions on the router. This privilege escalation allows the attacker to gain complete control over the device, enabling them to modify network configurations, install malicious software, or establish persistent backdoors. The vulnerability is particularly concerning because it allows remote code execution without requiring authentication, meaning that an attacker can exploit this flaw from outside the local network. The attack surface is further expanded by the fact that the web interface is typically accessible from the internet, making this vulnerability an attractive target for automated exploitation campaigns.
The operational impact of this vulnerability extends far beyond the immediate compromise of individual devices, as routers serve as critical network infrastructure components that control traffic flow, implement security policies, and provide network access for multiple devices. When a router is compromised through this vulnerability, attackers can manipulate DNS settings, redirect traffic through malicious servers, or establish man-in-the-middle positions to intercept sensitive communications. The attack pattern aligns with techniques described in the MITRE ATT&CK framework under the T1059.001 tactic for command and scripting interpreter, where adversaries use legitimate system tools to execute malicious code. Network administrators may not immediately detect compromise of these devices due to the stealthy nature of the attack and the limited logging capabilities of consumer-grade routers, allowing attackers to maintain persistence for extended periods.
Mitigation strategies for this vulnerability require immediate firmware updates from D-Link, as the vendor should release patches that address the improper input validation in the system() function call. Network segmentation and firewall rules should be implemented to restrict access to the router's web interface from untrusted networks, though this approach is only partially effective given that the vulnerability allows for remote exploitation without authentication. Security monitoring should include detection of unusual network traffic patterns that might indicate command execution or data exfiltration from compromised devices. Organizations should consider implementing network access control lists that restrict access to router management interfaces and deploy intrusion detection systems capable of identifying exploitation attempts targeting this specific vulnerability. The remediation process should also include comprehensive network scanning to identify all affected devices and ensure that firmware updates are properly applied across the entire network infrastructure. Additionally, network administrators should implement regular vulnerability assessments and penetration testing to identify similar weaknesses in other network equipment that may be susceptible to similar command injection vulnerabilities.