VulnerabilityPublished 18 Mar 2026Updated 19 Mar 2026

CVE-2026-30704: Hidden Functionality

Source CVE Database V5

Not known to be exploited · CVSS 9.1 Critical.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate this vulnerability, organizations should implement strict physical security controls to prevent unauthorized access to network devices, especially the WiFi Extender WDR201A units. This includes securing device enclosures, restricting access to wiring closets or network rooms, and monitoring for tampering. Network segmentation can limit the impact of a compromised device by isolating it from critical systems. Until a firmware patch or hardware revision is available, consider disabling or removing devices with this vulnerability from sensitive environments. If possible, inspect devices for exposed UART pads and physically block or cover them to prevent connection. Employ network monitoring to detect unusual traffic patterns or device behavior indicative of compromise. Engage with the device manufacturer to request firmware updates or hardware fixes that secure or disable the UART interface. Additionally, maintain an inventory of affected devices and track any updates or advisories related to this CVE. For environments where physical access cannot be fully controlled, consider alternative WiFi extenders or network devices with verified security controls.

Description

CVE-2026-30704 is a critical vulnerability affecting the WiFi Extender WDR201A (HW V2.1, FW LFMZX28040922V1.02) that exposes an unprotected UART interface via accessible hardware pads on the device's PCB. This vulnerability allows an attacker with physical access to the device to connect to the UART interface without any authentication or user interaction, potentially leading to full compromise of the device. The vulnerability has a CVSS score of 9.1, indicating high severity due to its network attack vector, no required privileges, and no user interaction needed. Exploitation can result in high confidentiality impact and high availability impact, though integrity impact is not indicated. No known exploits are currently reported in the wild, and no patches have been released. Organizations using this specific WiFi extender hardware should consider physical security controls and monitor for firmware updates. Countries with significant deployments of this device or similar hardware, especially where physical access to network devices is less controlled, are at higher risk.

Impact

The vulnerability poses a significant risk to organizations relying on the WiFi Extender WDR201A for network extension and connectivity. An attacker with physical access to the device can exploit the exposed UART interface to gain direct low-level access to the device, potentially extracting sensitive configuration data, credentials, or network traffic. This can lead to unauthorized network access, data breaches, and lateral movement within the network. The high availability impact means attackers could disrupt network services by disabling or bricking the device, causing denial of service. Since the vulnerability requires physical access, the risk is elevated in environments with less stringent physical security controls, such as public or semi-public spaces, shared office environments, or remote sites. The lack of authentication and user interaction requirements makes exploitation straightforward once physical access is obtained. The absence of patches increases the window of exposure, and the critical severity indicates that organizations should prioritize mitigation to prevent potential compromise or service disruption. The vulnerability could also undermine trust in network infrastructure and complicate incident response efforts if exploited.

CWE-912Hidden Functionality (opens in a new tab)
Class weakness
The product contains functionality that is not documented, not part of the specification, and not accessible through an interface or command sequence that is obvious to the product's users or administrators.
Installation
Always verify the integrity of the product that is being installed.
Attack patterns
Try All Common Switches (opens in a new tab)
Reverse Engineer an Executable to Expose Assumed Hidden Functionality (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 26 Mar 2026, 01:15 UTC

WeaknessesCWE-912

Technical details

References

Community reviews

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