CVE-2017-16249 in Debut Embedded http Server
Summary
by MITRE
The Debut embedded http server 1.20 contains a remotely exploitable denial of service where a single malformed HTTP request can cause the server to hang until eventually replying with an HTTP 500 error. While the server is hung, print jobs over the network are blocked and the web interface is inaccessible. An attacker can continuously send this malformed request to keep the device inaccessible to legitimate traffic. NOTE: this might overlap CVE-2017-12568.
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Analysis
by VulDB Data Team • 07/13/2024
The vulnerability identified as CVE-2017-16249 affects the Debut embedded HTTP server version 1.20, representing a critical denial of service weakness that can be exploited remotely without authentication. This flaw specifically targets the server's handling of malformed HTTP requests, creating a condition where the system becomes unresponsive and eventually responds with HTTP 500 errors. The vulnerability demonstrates characteristics consistent with CWE-400, which encompasses issues related to resource exhaustion and system instability caused by improper input handling. The affected system operates as an embedded HTTP server within a broader network printing solution, making it a potential target for attackers seeking to disrupt legitimate network operations.
The technical exploitation of this vulnerability occurs through the deliberate crafting of malformed HTTP requests that trigger the embedded server's failure to properly process incoming traffic. When such requests are received, the server enters a hung state where it cannot effectively handle concurrent requests or process legitimate print jobs through the network interface. This behavior represents a classic denial of service attack vector where the system's resources become tied up in processing invalid requests, preventing normal operational functions. The HTTP 500 error response indicates that while the server is not completely crashed, it has entered a state where it cannot properly respond to legitimate requests, effectively blocking access to the web interface and network printing capabilities.
The operational impact of this vulnerability extends beyond simple service disruption, as it fundamentally compromises the availability of network printing services that organizations depend upon for their daily operations. During the period when the server remains in the hung state, all print jobs submitted over the network are blocked, creating significant productivity losses and operational bottlenecks. The web interface becomes completely inaccessible, preventing administrators from monitoring or managing the device remotely, which compounds the operational disruption. This type of attack can be sustained indefinitely by continuously sending malformed requests, creating a persistent denial of service condition that can only be resolved through manual intervention or device reboot, aligning with ATT&CK technique T1499.004 for network denial of service.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and request sanitization within the embedded HTTP server component. Network-level protections such as intrusion detection systems and rate limiting can help detect and prevent the continuous sending of malformed requests that trigger the vulnerability. Additionally, organizations should consider implementing network segmentation to isolate affected devices and limit the potential impact of such attacks. The vulnerability's overlap with CVE-2017-12568 suggests that similar patterns of exploitation may exist within the same product line, warranting comprehensive vulnerability assessment across all embedded components. Regular firmware updates and patches from the vendor should be prioritized to address this weakness, while monitoring for unusual traffic patterns that might indicate exploitation attempts. Organizations should also implement redundancy measures and alternative printing solutions to maintain operational continuity during potential exploitation events.