CVE-2023-2799: Cnoa OA Auth Bypass Vulnerability

CVE-2023-2799 Overview

A hardcoded credentials vulnerability has been discovered in cnoa OA (Office Automation system) up to version 5.1.1.5. This vulnerability affects the login functionality at /index.php?app=main&func=passport&action=login, where the application utilizes hard-coded passwords. The presence of embedded credentials allows attackers to gain unauthorized access to the system without requiring any prior authentication or user interaction.

Critical Impact

This vulnerability enables unauthenticated remote attackers to bypass authentication mechanisms entirely by exploiting hard-coded credentials, potentially resulting in full system compromise including unauthorized data access, system modification, and service disruption.

Affected Products

• cnoa OA versions up to and including 5.1.1.5
• cnoa_oa_project cnoa_oa (all versions through 5.1.1.5)

Discovery Timeline

• 2023-05-18 - CVE-2023-2799 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-2799

Vulnerability Analysis

CVE-2023-2799 is a hardcoded credentials vulnerability (CWE-259) that exists within the cnoa OA office automation system. The vulnerability stems from the use of hard-coded passwords within the authentication module, specifically in the login handler located at /index.php?app=main&func=passport&action=login. This type of flaw represents a fundamental security design failure where credentials are embedded directly into the application code rather than being securely managed through proper credential storage mechanisms.

The exploit has been publicly disclosed, and the vendor was contacted about this vulnerability but did not respond. This lack of vendor response means affected organizations must take immediate defensive measures as no official patch is available.

Root Cause

The root cause of this vulnerability is the use of hard-coded passwords (CWE-259: Use of Hard-coded Password) within the application's authentication mechanism. Instead of implementing a secure credential management system that requires unique, user-configurable passwords, the developers embedded static credentials directly into the application. This practice violates fundamental secure development principles and creates a persistent backdoor that cannot be remediated through normal password management procedures.

Attack Vector

The attack vector for CVE-2023-2799 is network-based and requires no authentication or user interaction. An attacker can remotely access the vulnerable login endpoint at /index.php?app=main&func=passport&action=login and utilize the known hard-coded credentials to authenticate. The attack does not require any privileges and can be executed from any network location with access to the vulnerable system. Once authenticated using the embedded credentials, the attacker gains full access to the OA system with the privileges associated with the compromised account.

The vulnerability is particularly dangerous because the hard-coded credentials cannot be changed by administrators without modifying the application source code, and may persist even after password resets for other accounts.

Detection Methods for CVE-2023-2799

Indicators of Compromise

• Successful login events from unexpected IP addresses or geographic locations to the cnoa OA system
• Authentication attempts using the default or hard-coded credentials against /index.php?app=main&func=passport&action=login
• Unusual access patterns or administrative actions performed by accounts that should not have elevated privileges
• Multiple rapid authentication requests targeting the login endpoint from external sources

Detection Strategies

• Implement network monitoring to detect and alert on access attempts to the vulnerable endpoint /index.php?app=main&func=passport&action=login
• Deploy web application firewall (WAF) rules to monitor and log authentication requests to cnoa OA systems
• Configure SIEM rules to correlate login events with known indicators of the hard-coded credential exploitation
• Review authentication logs for successful logins that do not correspond to legitimate user activity

Monitoring Recommendations

• Enable detailed logging for all authentication events on cnoa OA systems
• Monitor for any access to the system from untrusted network segments or external IP ranges
• Set up alerts for successful authentications outside of normal business hours
• Implement user behavior analytics to detect anomalous post-authentication activity

How to Mitigate CVE-2023-2799

Immediate Actions Required

• Isolate cnoa OA systems from direct internet exposure by placing them behind VPN or internal network segments only
• Implement network-level access controls to restrict access to the application from trusted IP addresses only
• Review and audit all existing user accounts and sessions for signs of unauthorized access
• Consider taking the system offline if it contains sensitive data until a proper mitigation strategy is in place

Patch Information

No official patch is available from the vendor at this time. The vendor was contacted regarding this vulnerability but did not respond. Organizations using cnoa OA should contact the vendor directly for remediation guidance or consider alternative solutions. Technical details about this vulnerability are available at VulDB #229376 and additional documentation can be found at the GitHub vulnerability report.

Workarounds

• Restrict network access to the cnoa OA system to only trusted internal networks using firewall rules
• Implement a reverse proxy with additional authentication layers before the cnoa OA login endpoint
• Deploy a Web Application Firewall (WAF) to monitor and potentially block suspicious authentication attempts
• Consider migrating to an alternative office automation system with proper credential management if the vendor does not provide a fix

# Example: Restrict access to cnoa OA using iptables (Linux)
# Allow only trusted internal network (example: 192.168.1.0/24)
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP