Vulnerability Assessment
| Impact | While formal CVSS and EPSS scores are not available for this CVE, the real-world risk assessment must account for the attack vector being physical, which significantly reduces the threat surface compared to remote exploits. An attacker requires physical possession of the device and basic soldering or connector skills to exploit this vulnerability. However, the absence of a CVSS vector should not minimize concern: the technical impact is high (information disclosure of sensitive firmware, credentials, and configuration data), the attack complexity is low to moderate (commodity tools and published research exist), and privilege escalation is not required. The presence of published security research (referenced via mstreet97.github.io) with detailed vulnerability disclosure indicates proof-of-concept information is publicly available, which increases the practical risk for users with devices in less secure physical locations or for adversaries with supply chain access. This is a legitimate priority for affected device owners, particularly in enterprise deployments or environments where device theft or physical tampering is a realistic threat model, though it is not a critical remote vulnerability. |
| Exploit ScenarioDerived | An attacker with physical access to a WiFi Extender WDR201A (for example, after purchasing a used or refurbished unit, or in a retail/warehouse environment) removes the device casing and uses basic soldering equipment or a UART connector to attach to the exposed PCB pads. Using a USB-to-UART adapter and terminal software, the attacker connects to the UART interface and immediately gains console access to the bootloader or running firmware without authentication, allowing them to dump the entire firmware image, extract embedded credentials or keys, or access configuration data stored in memory. This scenario is practical because it requires only five to ten dollars of hardware tools and published instructions (available in the referenced security research), making it a credible threat for supply chain compromise or targeted attacks on specific high-value targets. |
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Alert meAnalysisAIv1 – Mar 18, 2026
The WiFi Extender WDR201A (hardware version 2.1, firmware LFMZX28040922V1.02) contains an unprotected UART interface exposed through accessible PCB pads, allowing information disclosure through direct hardware access. An attacker with physical access to the device can connect to the UART pins to read sensitive data, firmware contents, or configuration information without authentication. No CVSS score, EPSS metric, or KEV status is currently available, but a proof-of-concept and detailed security research have been published, confirming the vulnerability's practical exploitability.
RemediationAI
Owners of the affected WDR201A (HW V2.1, FW LFMZX28040922V1.02) should contact the manufacturer to determine if a firmware update is available that disables or protects the UART interface. If a patch is available, apply it immediately to production devices. As an interim mitigation, restrict physical access to affected devices by placing them in secure, monitored locations or within locked equipment cabinets to prevent unauthorized UART access. Organizations should also conduct an inventory of affected devices and assess whether any credentials, keys, or sensitive data may have been exposed if devices have been in untrusted environments (e.g., returned for service, refurbished units, or supply chain handling). For new deployments, verify that replacement units or alternative WiFi extender models implement secure hardware design practices, including disabled or authenticated debug interfaces. Manufacturers should consult the detailed security research at https://mstreet97.github.io/security-research/iot/vulnerability-disclosure/cybersecurity/cve/2026/02/18/From-Blackbox-to-Whitebox-Multiple-CVEs-in-a-Consumer-WiFi-Extender.html for comprehensive remediation guidance and hardware design recommendations.
Affected VersionsENISA
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Technical ContextAI · show details
The vulnerability stems from a lack of physical access controls and UART authentication mechanisms on the device's hardware interface. UART (Universal Asynchronous Receiver-Transmitter) is a common serial communication protocol used in embedded devices for debugging and firmware updates, typically accessible during manufacturing and development. The affected WiFi Extender model WDR201A exposes this UART interface through unprotected PCB pads that can be soldered or connected to without requiring any special tools beyond basic electronics equipment. This falls under improper access control and information disclosure (related to CWE-284: Improper Access Control), as the device fails to implement authentication, encryption, or physical tamper detection on the UART debug interface. The root cause is inadequate secure hardware design practices during device development, where debug interfaces were not disabled or protected in production firmware.
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DescriptionCVE.org
The WiFi Extender WDR201A (HW V2.1, FW LFMZX28040922V1.02) exposes an unprotected UART interface through accessible hardware pads on the PCB
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
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EUVD-2026-12878
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