CVE-2026-77877 in Control Web Panel
Summary
by MITRE • 11/02/2026
Control Web Panel (CWP) before webpanel_version 1.30 contains a missing authentication vulnerability that allows attackers able to reach the loopback API service to invoke root-privileged API routes without presenting an access token. Attackers can access endpoints such as /v1/restoredatabase/, /generaluser/, /last_access/, /valid_user/, /valid_token/, and /user_panel_dashboard/ to perform unauthorized actions with root privileges.
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Analysis
by VulDB Data Team • 11/02/2026
The Control Web Panel, a widely used hosting control panel software for managing Linux servers, contains a critical authentication bypass vulnerability in versions prior to 1.30 of the webpanel component. This flaw stems from an improper implementation of access controls within the internal loopback API service, which is designed to handle communication between different components of the system and external clients. The core technical deficiency lies in the failure to enforce strict authentication requirements for specific administrative endpoints when accessed via localhost or 127.0.0.1. Consequently, any process running on the local machine that can reach this loopback interface can invoke API routes that are intended to be restricted to authenticated administrators with root privileges. This architectural oversight effectively nullifies the security boundary between unprivileged user processes and privileged system administration functions, creating a significant attack surface for lateral movement or privilege escalation within the server environment.
The operational impact of this vulnerability is severe, as it allows attackers who have achieved any level of code execution on the target system to escalate their privileges to root without needing valid credentials. By exploiting the missing authentication mechanism, an attacker can interact with sensitive endpoints such as /v1/restoredatabase/, which may allow for database manipulation or restoration attacks; /generaluser/ and /valid_user/, which facilitate unauthorized user management including creation of new administrative accounts; /last_access/ and /valid_token/, which could be used to bypass session validation mechanisms; and /user_panel_dashboard/, providing access to the full control panel interface. These actions enable a wide range of malicious activities, including but not limited to creating backdoor users, modifying system configurations, accessing sensitive data stored in databases managed by the control panel, and potentially compromising other virtual hosts or services hosted on the same server. The ability to perform these actions with root privileges means that an attacker gains complete control over the underlying operating system and all applications running within it.
From a classification perspective, this vulnerability aligns directly with CWE-287, which describes Improper Authentication, specifically where authentication is bypassed for certain functions or endpoints. It also relates to CWE-862, Missing Authorization, as the API routes lack proper checks to ensure that the caller has the necessary permissions before executing privileged operations. In terms of adversary tactics and techniques, this flaw facilitates privilege escalation within a confined environment, mapping closely to MITRE ATT&CK technique T1078, Valid Accounts, where attackers use legitimate credentials or access mechanisms they have obtained through other means to maintain persistence and escalate privileges. Furthermore, the exploitation via loopback interfaces highlights risks associated with local service exposure, which can be categorized under lateral movement techniques if an attacker moves from a compromised web application to the control panel interface running on localhost.
Mitigation strategies for this vulnerability primarily involve upgrading Control Web Panel to version 1.30 or later, where these authentication checks have been properly implemented and enforced across all API endpoints regardless of the source IP address. For systems that cannot be immediately upgraded, administrators should consider restricting access to the loopback interface through firewall rules if possible, although this may impact legitimate internal communications between CWP components. Additionally, implementing strict file permissions on configuration files and ensuring that no untrusted users have shell access or code execution capabilities on the server is crucial for defense in depth. Security monitoring should be enhanced to detect unusual API calls originating from localhost, particularly those targeting administrative endpoints like /v1/restoredatabase/ or user management routes, as these may indicate an active exploitation attempt against this vulnerability. Regular audits of installed software versions and prompt application of security patches are essential practices to prevent such authentication bypasses in enterprise environments relying on Control Web Panel for server administration.