CVE-2025-51281 in D-Link DI-8100
Summary
by MITRE • 08/26/2025
D-Link DI-8100 16.07.26A1 is vulnerable to Buffer Overflow via the en`, `val and id parameters in the qj_asp function. This vulnerability allows authenticated attackers to cause a Denial of Service (DoS) by sending crafted GET requests with overly long values for these parameters.
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Analysis
by VulDB Data Team • 08/26/2025
The vulnerability identified as CVE-2025-51281 affects D-Link DI-8100 routers running firmware version 16.07.26A1, representing a critical buffer overflow condition within the device's web interface handling mechanism. This flaw exists in the qj_asp function which processes incoming HTTP GET requests containing the en, val, and id parameters, creating an avenue for authenticated attackers to exploit the system's memory management weaknesses. The vulnerability stems from inadequate input validation and bounds checking within the router's firmware, specifically in how it handles parameter values passed through the web administration interface.
The technical implementation of this buffer overflow occurs when the qj_asp function processes user-supplied parameters without proper length verification or memory boundary enforcement. When an authenticated attacker crafts a GET request with excessively long values for the en, val, or id parameters, the system fails to validate the input lengths against allocated buffer sizes, leading to memory corruption. This memory corruption manifests as a system crash or reboot, effectively causing a denial of service condition that renders the router unavailable to legitimate users. The vulnerability operates at the application layer within the web server component of the router's firmware, making it accessible through standard HTTP protocols and requiring only authentication credentials to exploit.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged for more sophisticated attacks within network environments. An authenticated attacker with access to the router's administrative interface can repeatedly trigger the buffer overflow condition to maintain persistent denial of service, potentially disrupting network connectivity for all devices relying on the affected router. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous in environments where network availability is critical. Network administrators may face challenges in detecting this attack as it appears as routine administrative activity, while the actual exploitation remains hidden within legitimate traffic patterns.
Mitigation strategies for CVE-2025-51281 should prioritize immediate firmware updates from D-Link, as this represents the most effective solution to address the underlying buffer overflow implementation flaw. Network segmentation and access control measures can help limit the attack surface by restricting administrative access to the router to only authorized personnel and systems. Implementing intrusion detection systems capable of identifying abnormal parameter lengths in HTTP GET requests can provide early warning of potential exploitation attempts. Additionally, network administrators should consider disabling unnecessary web administration interfaces and implementing strong authentication measures including multi-factor authentication to reduce the likelihood of unauthorized access. This vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflow conditions, and its exploitation patterns correspond to ATT&CK technique T1499.004 for network disruption and T1566.001 for credential access through web application attacks, making it a significant concern for enterprise network security posture management.