CVE-2026-9033 in ER7212PC
Summary
by MITRE • 08/20/2026
An unauthenticated attacker with network access to the captive portal service of an affected device can terminate active captive portal sessions, including forcing logout of specific users or clearing all active sessions. Affected users must re-authenticate to regain access.
Successful exploitation may allow termination of individual or all active captive portal sessions, causing temporary service disruption and requiring users to re-authenticate.
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Analysis
by VulDB Data Team • 08/21/2026
The vulnerability described constitutes a significant availability risk within the authentication infrastructure of network devices employing captive portals. This flaw allows an unauthenticated attacker who possesses basic network connectivity to interact with the captive portal service in ways that were not intended by the system designers. Specifically, the attacker can exploit this weakness to terminate active sessions for specific users or clear all active sessions simultaneously. Because the vulnerability does not require prior authentication, it represents a low-barrier entry point for malicious actors who are already on the local network segment where the captive portal operates. This lack of access control is particularly concerning in public Wi-Fi environments such as airports, hotels, and coffee shops, where users connect to open networks before being redirected to a login page.
From a technical perspective, this issue likely stems from insufficient validation or authorization checks within the session management logic of the captive portal application. The service appears to accept requests that invalidate sessions without verifying whether the requester has legitimate administrative privileges or ownership over those specific sessions. In many web-based authentication systems, session termination is an action reserved for administrators or requires a valid session token associated with the user whose session is being terminated. By bypassing these checks, the attacker can send crafted HTTP requests to the server that instruct it to destroy active state information. This could involve manipulating session identifiers sent in cookies or URL parameters, exploiting a logic flaw where the server trusts client-supplied data regarding which sessions should be ended without cross-referencing against an access control matrix.
The operational impact of this vulnerability is primarily centered on service availability and user experience degradation rather than direct data theft or system compromise. When active sessions are forcibly terminated, users who have already authenticated to gain internet access are immediately disconnected from the network. They must then re-authenticate by returning to the captive portal login page and completing the authentication process again. This creates a denial of service condition for legitimate users, leading to frustration and potential loss of productivity or connectivity-dependent tasks such as video conferencing or large file transfers. In high-traffic environments, an attacker could repeatedly trigger this action against multiple sessions, effectively creating a persistent disruption that degrades the quality of service provided by the network administrator.
This vulnerability aligns with several established security classifications within industry standards. It is best categorized under CWE-284 Improper Access Control, as the system fails to restrict actions based on user roles or permissions. Additionally, it relates to CWE-613 Insufficient Session Expiration if the session management logic allows indefinite termination by unauthorized parties due to poor state validation. From an offensive security perspective, this behavior can be mapped to MITRE ATT&CK technique T1529 System Shutdown/Reboot in the context of service disruption, although more specifically it falls under denial-of-service mechanisms that target application-level availability rather than infrastructure components. The ability to force logout is a form of session hijacking or manipulation where the attacker disrupts the continuity of authenticated interactions without needing to steal credentials.
Mitigation strategies for this vulnerability should focus on implementing robust access control measures within the captive portal service. Developers must ensure that any action involving session termination, such as logging out users or clearing sessions, is strictly protected by authentication and authorization checks. Only administrators with valid administrative credentials should be able to terminate arbitrary user sessions, while individual users should only be able to terminate their own active sessions after verifying their identity through the current authenticated context. Furthermore, implementing rate limiting on session management endpoints can help mitigate automated attacks that attempt to flood the service with termination requests. Network segmentation and firewall rules can also restrict access to the captive portal administrative interfaces from untrusted network zones, ensuring that only authorized devices or IP ranges can interact with sensitive authentication functions. Regular security testing including penetration tests focused on authorization bypasses is essential to identify such logic flaws before deployment in production environments.