CVE-2026-78167: ipTIME T16000M Authentication Bypass Flaw

CVE-2026-78167 Overview

CVE-2026-78167 is an authentication bypass vulnerability affecting the EFM ipTIME T16000M router running firmware version 14.20.2. The flaw resides in the httpcon_check_session_url function within the Session Validation Handler component. Improper authentication logic [CWE-287] allows remote attackers to bypass session validation without valid credentials. Public exploit code is available, and the vendor did not respond to disclosure attempts. The vulnerability is network-exploitable and requires no user interaction or prior privileges.

Critical Impact
Remote unauthenticated attackers can bypass session validation on affected ipTIME T16000M routers, gaining access to protected router functions and compromising network confidentiality, integrity, and availability.

Affected Products

EFM ipTIME T16000M router firmware version 14.20.2
Session Validation Handler component (httpcon_check_session_url function)
Deployments where the router administrative interface is reachable over the network

Discovery Timeline

2026-08-24 - CVE-2026-78167 published to NVD
2026-08-24 - Last updated in NVD database

Technical Details for CVE-2026-78167

Vulnerability Analysis

The vulnerability is an improper authentication weakness [CWE-287] in the EFM ipTIME T16000M router's HTTP session handling logic. The httpcon_check_session_url function is responsible for validating user sessions before granting access to protected administrative URLs. Faulty logic in this function allows attackers to reach protected functionality without a valid authenticated session.

Because the flaw lives in the session validation path itself, the router's downstream authorization checks inherit the incorrect trust decision. An attacker who reaches the web interface can therefore act as if they hold a legitimate session. Public disclosure has already occurred, and exploit material is available in the referenced repositories.

Root Cause

The root cause is flawed session verification inside httpcon_check_session_url. The function fails to correctly reject requests that lack a valid session token or that supply manipulated session identifiers. Requests that should return an authentication failure instead pass validation and are routed to privileged handlers.

Attack Vector

Exploitation is remote and network-based. An attacker sends crafted HTTP requests to the router's management interface targeting URLs protected by httpcon_check_session_url. No credentials, user interaction, or local access are required. Devices exposing the management interface to untrusted networks or the internet are at highest risk. Refer to the VulDB entry for CVE-2026-78167 and GitHub CVE Issue #2 for technical details.

Detection Methods for CVE-2026-78167

Indicators of Compromise

HTTP requests to authenticated router management paths that succeed without a preceding successful login event.
Access to router configuration endpoints from external or unexpected source IP addresses.
Unusual configuration changes, new administrative accounts, or altered DNS and firewall settings on the ipTIME T16000M.

Detection Strategies

Inspect router HTTP access logs for requests to session-protected URLs that lack corresponding authenticated session cookies.
Correlate management-interface traffic against a baseline of known administrative source addresses.
Alert on repeated access to the ipTIME administrative endpoints from WAN-facing interfaces.

Monitoring Recommendations

Forward router syslog and HTTP audit logs to a central SIEM for long-term retention and correlation.
Monitor for DNS, DHCP, and routing configuration drift on affected devices.
Watch outbound traffic from the router itself for anomalous connections that could indicate post-exploitation activity.

How to Mitigate CVE-2026-78167

Immediate Actions Required

Restrict access to the ipTIME T16000M web management interface to trusted internal subnets only, and disable WAN-side administration.
Place affected routers behind a network segmentation boundary and block inbound HTTP/HTTPS to the management port from untrusted networks.
Audit administrative accounts and configuration on affected devices and rotate any credentials that may have been exposed.

Patch Information

No vendor patch is currently referenced in the CVE data. The vendor was contacted but did not respond to the disclosure. Monitor the EFM ipTIME support channel and vendor firmware release pages for updated firmware superseding version 14.20.2. Until a fix is published, treat affected devices as exposed and apply compensating controls.

Workarounds

Disable remote management on the WAN interface and permit administration only from a dedicated management VLAN.
Enforce access control lists (ACLs) at upstream firewalls to block inbound traffic to the router's HTTP/HTTPS management ports.
Replace end-of-support or unpatched devices with firmware-supported alternatives if a fix is not made available in a reasonable window.

bash

# Example firewall rule to block external access to router management (adapt to your platform)
iptables -A INPUT -i wan0 -p tcp --dport 80 -j DROP
iptables -A INPUT -i wan0 -p tcp --dport 443 -j DROP