CVE-2021-43718 in EH-TW5350
Summary
by MITRE • 08/18/2026
An Authentication Bypass vulnerability exists in EPSON EH-TW5350 EPSON 150075647YWWV110, which could let a remote malicious user cause a Denial of Service via specially crafted series of HTTP..
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Analysis
by VulDB Data Team • 08/18/2026
The identified security flaw represents a critical authentication bypass vulnerability within the firmware version 150075647YWWV110 of the EPSON EH-TW5350 projector. This specific device, widely deployed in educational and corporate presentation environments, relies on web-based management interfaces for configuration and control. The vulnerability stems from an insufficient validation mechanism within the HTTP request processing logic, allowing unauthenticated actors to interact with administrative functions or trigger internal processes without providing valid credentials. By exploiting this weakness, a remote attacker can bypass standard access controls that are designed to restrict sensitive operations to authorized administrators only. This fundamental breakdown in authentication integrity undermines the security boundary of the device, effectively granting unauthorized users elevated privileges within the local network context where the projector resides.
The operational impact of this vulnerability is primarily characterized by its potential to induce a Denial of Service condition through specially crafted HTTP requests. While many authentication bypasses lead directly to data exfiltration or remote code execution in more complex systems, the specific manifestation here involves resource exhaustion or state corruption triggered by malformed input sequences. An attacker can send a series of carefully constructed HTTP packets that exploit the parsing logic error, causing the device's web server or underlying operating system components to enter an unstable state. This instability results in the projector becoming unresponsive, freezing during critical presentations, or requiring a hard reset to restore functionality. In high-stakes environments such as live conferences or classroom settings, this disruption can lead to significant operational downtime and loss of productivity, serving as a potent vector for disruptive attacks rather than stealthy data theft.
From a technical classification perspective, this vulnerability aligns with CWE-287, which denotes Improper Authentication, specifically regarding the failure to correctly verify identity before granting access or performing actions. Furthermore, the exploitation technique maps directly to MITRE ATT&CK tactic T1078, Valid Accounts, as it involves bypassing standard authentication mechanisms to gain unauthorized access. The method of delivery via HTTP requests places this within the context of network-based attacks that target application-layer services. The reliance on crafted HTTP sequences suggests a potential interaction with buffer handling or state machine logic errors common in embedded web servers used in consumer electronics and IoT devices, where input sanitization is often less rigorous than in enterprise-grade software applications.
Mitigation strategies for this vulnerability require immediate attention from both the manufacturer and end-users. Epson should release a firmware update that patches the authentication validation logic to ensure all administrative endpoints strictly enforce credential verification before processing requests. Until such an update is available, network administrators must implement compensating controls at the infrastructure level. This includes placing the projector behind firewalls or access control lists that restrict HTTP management interface access exclusively to trusted IP addresses within the local subnet. Additionally, disabling unused web services if they are not required for operation can reduce the attack surface. Users should also ensure their internal network segmentation isolates IoT devices from critical data networks to limit the potential blast radius of any successful exploitation attempt aimed at causing denial of service or further lateral movement.