CVE-2025-61577 in DIR-816A2
Summary
by MITRE • 10/09/2025
D-Link DIR-816A2_FWv1.10CNB05 was discovered to contain a stack overflow via the statuscheckpppoeuser parameter in the dir_setWanWifi function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted input.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/09/2025
The vulnerability identified as CVE-2025-61577 affects the D-Link DIR-816A2 router firmware version 1.10CNB05 and represents a critical stack overflow condition within the device's web interface handling mechanism. This flaw exists in the dir_setWanWifi function where the statuscheckpppoeuser parameter is processed without adequate input validation or bounds checking, creating an exploitable condition that can be leveraged by remote attackers to disrupt normal device operations.
The technical implementation of this vulnerability stems from improper memory management within the router's firmware codebase where user-supplied input from the statuscheckpppoeuser parameter is directly processed into a stack-based buffer without sufficient size validation. This classic stack overflow condition occurs when the input exceeds the allocated buffer space, causing the program to overwrite adjacent memory locations and potentially leading to arbitrary code execution or system instability. The vulnerability manifests specifically during the processing of PPPoE user status checks, indicating that the issue is tied to the router's WAN connection management functionality.
From an operational perspective, this vulnerability presents a significant risk to network availability and security posture as it enables remote attackers to trigger a denial of service condition without requiring authentication or specialized privileges. The impact extends beyond simple service disruption since the stack overflow can potentially lead to complete system crashes, requiring manual intervention for recovery. Network administrators face the challenge of maintaining service availability while the device remains vulnerable, and the attack surface is particularly concerning given that the vulnerability is accessible through the web interface, which is commonly exposed to external networks.
The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which classifies this as a fundamental memory safety issue where insufficient bounds checking allows attackers to overwrite stack memory. This weakness falls under the ATT&CK technique T1499.004 for Network Denial of Service, demonstrating how attackers can leverage firmware vulnerabilities to compromise availability. The attack vector is particularly dangerous as it requires no authentication and can be executed through standard web browser interactions, making it accessible to a wide range of threat actors. Organizations should consider implementing network segmentation and access controls to limit exposure while awaiting official patches from D-Link.
Mitigation strategies should include immediate firmware updates from D-Link once available, network monitoring to detect suspicious traffic patterns, and temporary network segmentation to limit potential exploitation. The vulnerability highlights the importance of secure coding practices and comprehensive input validation in embedded systems, particularly in network infrastructure devices where availability is paramount. Security teams should also consider implementing intrusion detection systems to monitor for exploitation attempts and establish incident response procedures for handling such vulnerabilities in production environments.