CVE-2017-17065 in DIR-605L
Summary
by MITRE
An issue was discovered on D-Link DIR-605L Model B before FW2.11betaB06_hbrf devices, related to the code that handles the authentication values for HNAP. An attacker can cause a denial of service (device crash) or possibly have unspecified other impact by sending a sufficiently long string in the password field of the HTTP Basic Authentication section of the HTTP request.
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Analysis
by VulDB Data Team • 12/11/2019
The vulnerability identified as CVE-2017-17065 affects D-Link DIR-605L Model B devices running firmware versions prior to FW2.11betaB06_hbrf and represents a classic buffer overflow condition within the HTTP Basic Authentication handling mechanism. This issue specifically targets the HNAP (Home Network Access Protocol) implementation which serves as the primary interface for remote management of the device. The flaw exists in how the device processes authentication values, particularly when handling the password field within HTTP Basic Authentication headers. The vulnerability stems from inadequate input validation and bounds checking within the authentication parsing code, creating a condition where maliciously crafted input can trigger unexpected behavior in the device's processing logic.
The technical exploitation of this vulnerability involves sending a specially crafted HTTP request containing an excessively long string in the password field of the Basic Authentication header. This malformed input causes the device to attempt to process data beyond the allocated buffer space, leading to memory corruption that results in device instability. The buffer overflow condition manifests as a device crash or complete system failure, effectively rendering the router inaccessible to legitimate users and administrators. The vulnerability's impact extends beyond simple denial of service as the memory corruption could potentially lead to arbitrary code execution or other unspecified security implications depending on the specific memory layout and execution context when the overflow occurs.
From an operational perspective, this vulnerability presents significant risks to network availability and security posture for affected organizations and individuals. The device crash resulting from the exploit renders the router completely non-functional, requiring manual intervention for recovery including potential firmware reinstallation or physical device reset procedures. The vulnerability is particularly concerning because it can be exploited remotely without requiring authentication, making it accessible to any attacker with network access to the device. The impact on network infrastructure can be substantial as the DIR-605L serves as a primary network gateway for many small office and home environments, potentially causing widespread disruption to network services and connectivity.
The vulnerability aligns with CWE-121, which describes buffer overflow conditions in stack-based buffers, and represents a classic example of improper input validation in network service implementations. From an attack framework perspective, this vulnerability maps to several ATT&CK techniques including T1210 - Exploitation of Remote Services and T1499 - Endpoint Denial of Service, as the attack vector targets the device's HTTP service to achieve denial of service outcomes. The attack surface is particularly broad given that HTTP Basic Authentication is a standard protocol feature that is enabled by default on many network devices, making this vulnerability exploitable by automated scanning tools and attackers with minimal technical expertise. Organizations should prioritize patching affected devices and implementing network segmentation to limit the potential impact of such vulnerabilities. Additionally, monitoring for unusual HTTP traffic patterns and authentication attempts could help detect exploitation attempts before they result in service disruption.
The remediation approach for this vulnerability requires immediate firmware updates from D-Link to address the buffer overflow condition in the HNAP authentication handling code. Network administrators should also implement network access controls to limit exposure of affected devices to untrusted networks and consider disabling unnecessary services where possible. The vulnerability highlights the importance of proper input validation and bounds checking in embedded network device firmware, particularly for authentication mechanisms that handle user credentials and access control. Regular firmware update procedures and security assessments of network infrastructure should be implemented to prevent similar issues from affecting other network devices in the environment.