CVE-2026-25803: 3DP-MANAGER Auth Bypass Vulnerability

CVE-2026-25803 Overview

CVE-2026-25803 is a critical hardcoded credentials vulnerability affecting 3DP-MANAGER, an inbound generator for 3x-ui. The application automatically creates an administrative account with known default credentials (admin/admin) upon first initialization. Attackers with network access to the application's login interface can exploit this weakness to gain full administrative control over the system, enabling management of VPN tunnels and system settings.

Critical Impact

Attackers can leverage default credentials to obtain full administrative access to 3DP-MANAGER, compromising VPN tunnel configurations and system settings without requiring any prior authentication bypass techniques.

Affected Products

• 3DP-MANAGER version 2.0.1 and prior
• 3DP-MANAGER installations with default initial configuration
• Systems running 3x-ui with 3DP-MANAGER integration

Discovery Timeline

• 2026-02-06 - CVE CVE-2026-25803 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2026-25803

Vulnerability Analysis

This vulnerability falls under CWE-798 (Use of Hard-coded Credentials), a design flaw where the application embeds fixed authentication credentials within its initialization process. During the first startup, 3DP-MANAGER automatically provisions an administrative account with the well-known credentials admin/admin. This implementation pattern creates an immediate security exposure as these credentials are publicly documented and trivially guessable.

The vulnerability is particularly dangerous because it requires no user interaction and can be exploited remotely over the network. Any attacker who can reach the application's login interface can attempt authentication using the default credentials, gaining complete administrative privileges over the VPN management infrastructure.

Root Cause

The root cause is the use of hardcoded default credentials during the application's initial setup process. Rather than forcing administrators to create unique credentials during installation or generating random initial passwords, the application defaults to a static username and password combination that is consistent across all deployments. This approach prioritizes ease of initial access over security, leaving systems vulnerable from the moment of deployment.

Attack Vector

The attack vector for this vulnerability is network-based, requiring only access to the 3DP-MANAGER login interface. An attacker can exploit this vulnerability by navigating to the application's authentication endpoint and submitting the default admin/admin credentials. Upon successful authentication, the attacker gains full administrative control, including the ability to create, modify, or delete VPN tunnels, alter system configurations, and potentially pivot to connected 3x-ui infrastructure.

The exploitation process is straightforward: identify a 3DP-MANAGER instance, access the login page, and authenticate using the known default credentials. No sophisticated tools or techniques are required, making this vulnerability accessible to attackers of all skill levels.

Detection Methods for CVE-2026-25803

Indicators of Compromise

• Successful authentication events using the admin username from unfamiliar or external IP addresses
• Multiple rapid login attempts followed by administrative configuration changes
• Creation of new VPN tunnels or modification of existing configurations by the default admin account
• Unusual access patterns to the 3DP-MANAGER administrative interface

Detection Strategies

• Monitor authentication logs for successful logins using the default admin account, especially from external networks
• Implement alerting on administrative actions performed shortly after initial login events
• Deploy network monitoring to identify reconnaissance activity targeting 3DP-MANAGER login endpoints
• Conduct periodic credential audits to verify default accounts have been disabled or reconfigured

Monitoring Recommendations

• Enable detailed authentication logging within 3DP-MANAGER and forward logs to a centralized SIEM
• Configure alerts for any successful authentication using known default usernames
• Monitor network traffic for access to the administrative interface from unauthorized sources
• Implement baseline behavior analysis to detect anomalous administrative activity

How to Mitigate CVE-2026-25803

Immediate Actions Required

• Change the default administrative credentials immediately upon installation and before exposing the service to any network
• Audit all existing 3DP-MANAGER deployments to verify default credentials are not in use
• Restrict network access to the administrative interface using firewall rules or network segmentation
• Upgrade to version 2.0.2 or later once available, which includes a patch for this vulnerability

Patch Information

The vendor has acknowledged this vulnerability and confirmed that a fix will be included in version 2.0.2 of 3DP-MANAGER. The patch commit is available in the GitHub repository. Organizations should monitor for the release and apply the update as soon as it becomes available. Full details are documented in the GitHub Security Advisory.

Workarounds

• Immediately change the default admin password to a strong, unique credential upon initial deployment
• Disable or remove the default administrative account and create a new administrator account with unique credentials
• Implement IP-based access restrictions to limit administrative interface access to trusted networks only
• Deploy a reverse proxy with additional authentication layers in front of the 3DP-MANAGER interface

# Configuration example
# Restrict access to 3DP-MANAGER admin interface via firewall
# Allow only trusted management network (example: 10.0.1.0/24)
iptables -A INPUT -p tcp --dport 8080 -s 10.0.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP