External risk intelligence

EFM ipTIME A3004T Session Validation Improper Authentication Vulnerability.

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-19977

The product is a consumer-grade router/gateway device. The vulnerability resides in the session validation component of the HTTP interface, which is a management surface designed to be accessible over the network. Such devices are commonly exposed to the internet by design or via common deployment configurations to facilitate remote administration.

Authentication Bypass

Halo Surface Signal: 5 out of 5 — more likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in certain network devices, specifically in their session validation function. This issue allows for remote exploitation, and an exploit is publicly available, increasing the potential risk to affected systems. The vendor has not responded to inquiries regarding this disclosure.

Improper authentication allows remote access.
Public exploit increases risk to network devices.
Confirm relevance and exposure of affected devices.

Attack Path

How an attacker could exploit the issue

Attackers can reach and trigger this vulnerability by interacting with the router's web interface, which is often exposed to the internet. Once they reach the session validation function, they can manipulate it to bypass authentication, potentially leading to a complete compromise of the device's security.

Entry condition: Network access to the router's interface.
Trigger point: Manipulating the session validation function.
Resulting risk: Improper authentication and full device compromise.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could affect the session validation on affected devices, potentially allowing unauthorized access when the HTTP management interface is accessible.

Device access and control.
Remote, unauthenticated manipulation.
Compromise of network security.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in EFM ipTIME A3004T's session validation function requires immediate attention from infrastructure and network security teams. The first practical step is to identify all instances of this device within your network, determine their exposure to external networks, and confirm their business criticality. Subsequently, locate the accountable owner for each instance to collaboratively plan remediation, prioritizing high-risk or critical assets.

Infrastructure and security teams own the fix.
Verify external reachability and criticality.
Plan remediation based on exposure risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the EFM ipTIME A3004T?

The EFM ipTIME A3004T is a consumer-grade wireless router and gateway device. It provides network connectivity and routing services for homes or small offices. Like many similar networking products, it includes an HTTP-based management interface that allows users to configure settings, monitor traffic, and manage security options via a web browser.

What does CWE-287 mean for CVE-2026-19977?

CVE-2026-19977 relates to CWE-287, which is the weakness class for Improper Authentication. In the context of this vulnerability, it means the router's session validation logic fails to correctly verify the identity of a user or the legitimacy of a request. Because the mechanism intended to gate access is flawed, an attacker can bypass these checks and interact with the device's administrative functions without providing valid credentials.

How is this vulnerability triggered?

An attacker triggers this flaw by interacting with the specific session validation function in the device's web management interface. Successful exploitation does not require the attacker to have existing account credentials or physical access to the hardware. However, the flaw is not triggered by standard network traffic passing through the router; it specifically requires directed interaction with the HTTP management service itself.

Is my device at risk of this CVE?

According to Halo Surface Signal, this vulnerability is highly relevant because the affected component is part of the management interface, which is often exposed to the network. Devices that are accessible from the internet are at the highest risk, as remote attackers can reach the interface directly. Even if a device is only accessible from an internal network, it remains vulnerable to any actor or compromised system already present on that local network.

What should I do to secure my environment?

The immediate priority is to identify all EFM ipTIME A3004T devices within your infrastructure. Once identified, verify whether their web management interfaces are exposed to the internet and restrict access to these interfaces to trusted, internal networks only. Because the vendor has not responded to this disclosure, monitor the device manufacturer's official support channels or website regularly for any future firmware updates that might address this authentication flaw.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.