CVE-2001-1137 in Dl-704
Summary
by MITRE
D-Link DI-704 Internet Gateway firmware earlier than V2.56b6 allows remote attackers to cause a denial of service (reboot) via malformed IP datagram fragments.
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Analysis
by VulDB Data Team • 08/28/2024
The vulnerability identified as CVE-2001-1137 affects D-Link DI-704 Internet Gateway devices running firmware versions prior to V2.56b6, representing a critical security flaw that enables remote attackers to trigger unauthorized device reboots. This issue stems from inadequate handling of IP datagram fragments within the device's network processing stack, creating a denial of service condition that can be exploited from remote locations without requiring authentication or specialized privileges. The vulnerability specifically targets the device's packet fragmentation processing mechanism, where malformed IP fragments are not properly validated or sanitized before being processed by the gateway's operating system.
The technical implementation of this vulnerability resides in the network protocol stack of the D-Link DI-704 firmware, where the device fails to properly validate the fragmentation headers and data within IP packets. When malformed IP datagram fragments are received, the device's processing routine does not adequately check for valid fragment offsets, fragment lengths, or overlapping fragment boundaries that would indicate malicious or malformed input. This failure in input validation creates a condition where specially crafted IP fragments can cause the device's network processing components to crash or enter an unstable state, ultimately resulting in an automatic reboot of the device. The vulnerability operates at the network layer of the OSI model, specifically affecting the IP protocol implementation within the embedded firmware environment.
From an operational perspective, this vulnerability presents a significant risk to network availability and business continuity, as remote attackers can repeatedly trigger device reboots without requiring physical access or credentials. The impact extends beyond simple service disruption, as frequent reboots can lead to network outages, data loss, and potential compromise of network security posture. The device's automatic reboot behavior creates a persistent DoS condition that can be maintained indefinitely by an attacker, effectively rendering the gateway non-functional until manual intervention occurs. Organizations relying on this device for network connectivity face potential exposure to attackers who may use this vulnerability as a stepping stone for more sophisticated attacks or to disrupt critical network services.
The vulnerability aligns with CWE-129, which describes improper validation of input boundaries, and represents a classic example of a buffer overflow or input validation failure within network protocol processing. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service and T1566.001 for initial access through network services. The attack surface is particularly concerning given that the vulnerability does not require authentication and can be exploited from any location on the internet, making it a prime target for automated scanning and exploitation tools. Network administrators should implement immediate mitigations including firmware updates to version 2.56b6 or later, network segmentation to limit exposure, and monitoring for unusual reboot patterns or suspicious network traffic patterns that may indicate exploitation attempts.
Mitigation strategies should include immediate firmware upgrades to the patched version, implementation of network access controls to restrict unauthorized access to the device management interfaces, and deployment of intrusion detection systems to monitor for exploitation attempts. Organizations should also consider implementing network monitoring solutions that can detect anomalous fragmentation patterns and unusual reboot activity. The vulnerability highlights the importance of proper input validation in embedded network devices and demonstrates how seemingly minor protocol processing flaws can result in significant operational impacts. Regular vulnerability assessments and network monitoring should be conducted to identify similar issues in other network infrastructure components, as this type of vulnerability is commonly found in embedded systems with insufficient security hardening.