CVE-2002-1865 in BEFW11S4
Summary
by MITRE
Buffer overflow in the Embedded HTTP server, as used in (1) D-Link DI-804 4.68, Dl-704 V2.56b6, and Dl-704 V2.56b5 and (2) Linksys Etherfast BEFW11S4 Wireless AP + Cable/DSL Router 1.37.2 through 1.42.7 and Linksys WAP11 1.3 and 1.4, allows remote attackers to cause a denial of service (crash) via a long header, as demonstrated using the Host header.
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Analysis
by VulDB Data Team • 09/16/2024
The vulnerability identified as CVE-2002-1865 represents a critical buffer overflow flaw within embedded HTTP servers found in various networking devices from D-Link and Linksys. This issue affects multiple firmware versions of routers and wireless access points, specifically targeting the handling of HTTP headers during network communication. The vulnerability manifests when these devices receive HTTP requests containing excessively long headers, particularly the Host header, which triggers memory corruption in the embedded web server implementation. The affected products include D-Link DI-804 with firmware version 4.68, D-Link DL-704 series with versions 2.56b5 and 2.56b6, Linksys Etherfast BEFW11S4 Wireless AP + Cable/DSL Router with firmware versions 1.37.2 through 1.42.7, and Linksys WAP11 access points running versions 1.3 and 1.4.
The technical implementation of this vulnerability stems from inadequate input validation within the embedded HTTP server component. When processing incoming HTTP requests, the server fails to properly bounds-check the length of header fields before copying them into fixed-size memory buffers. This classic buffer overflow condition occurs because the device's firmware does not implement proper sanitization or length verification mechanisms for HTTP headers received from remote clients. The Host header, which is a standard HTTP header field, becomes particularly problematic when it exceeds the allocated buffer size, causing adjacent memory to be overwritten with attacker-controlled data. This memory corruption typically results in the embedded HTTP server crashing or becoming unresponsive, effectively rendering the network device inoperable.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with a reliable method to disrupt network services without requiring authentication or privileged access. Network administrators managing affected devices face significant operational challenges since the vulnerability can be exploited remotely over the network, meaning attackers do not need physical access to the devices to cause disruption. The affected devices essentially become unavailable for their intended purpose of routing network traffic, creating potential network outages that could affect multiple users or devices connected to the compromised network infrastructure. This vulnerability particularly impacts enterprise and home network environments where these devices serve as primary network access points, potentially causing widespread connectivity issues.
Organizations should implement immediate mitigations including firmware updates from manufacturers, network segmentation to limit exposure, and monitoring for suspicious HTTP traffic patterns. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation in embedded systems. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service attacks, and could potentially be leveraged as part of broader network reconnaissance or disruption campaigns. The lack of authentication requirements makes this particularly dangerous as it can be exploited by any remote attacker with network access to the affected devices, emphasizing the need for network-level protections and regular firmware maintenance across all embedded network infrastructure components.