CVE-2025-63800: Open Source Point Of Sale Auth Bypass

CVE-2025-63800 Overview

A weak password requirements vulnerability exists in Open Source Point of Sale (OSPOS) version 3.4.1 that allows authenticated users to set their account password to an empty string. The password change endpoint lacks proper server-side validation, enabling users to submit requests with empty password and repeat_password parameters. When these parameters are omitted or left blank, the backend incorrectly processes the request as successful and sets the account password to an empty string, effectively disabling authentication for that account.

Critical Impact

This vulnerability can lead to unauthorized access to user accounts, including administrative accounts, by allowing passwords to be set to empty strings, effectively bypassing authentication mechanisms.

Affected Products

• Open Source Point of Sale 3.4.1
• opensourcepos:open_source_point_of_sale

Discovery Timeline

• 2025-11-18 - CVE CVE-2025-63800 published to NVD
• 2025-12-19 - Last updated in NVD database

Technical Details for CVE-2025-63800

Vulnerability Analysis

This vulnerability is classified under CWE-521 (Weak Password Requirements), indicating a failure to enforce adequate password policies on user accounts. The password change endpoint in Open Source Point of Sale 3.4.1 does not implement proper server-side validation to ensure that passwords meet minimum complexity or length requirements. When an authenticated user submits a password change request without providing values for the password and repeat_password parameters, the application accepts the request and updates the account password to an empty string.

The flaw allows any authenticated user to effectively disable their own password protection or, in scenarios where an attacker has compromised an account temporarily, to lock out the legitimate user while maintaining unauthorized access. For administrative accounts, this vulnerability is particularly severe as it could grant attackers full control over the point of sale system.

Root Cause

The root cause of this vulnerability is missing server-side input validation on the password change functionality. The application fails to verify that the submitted password values are non-empty and meet minimum security requirements before updating the account credentials in the database. This represents a fundamental failure in implementing secure password management practices.

Attack Vector

The attack can be carried out over the network by any authenticated user. An attacker who gains temporary access to an account—through session hijacking, social engineering, or other means—can exploit this vulnerability to set the password to an empty string. This network-accessible attack vector requires no user interaction once the attacker has authenticated.

The exploitation process involves sending a POST request to the password change endpoint with empty or omitted password parameters. Since the backend does not validate the input, it processes the request successfully and stores an empty password hash, allowing subsequent authentication attempts with no password.

Detection Methods for CVE-2025-63800

Indicators of Compromise

• Database entries containing empty or null password hashes for user accounts
• Audit logs showing password change requests with empty parameter values
• Unusual authentication patterns where users log in without providing passwords
• Account access anomalies indicating potential unauthorized entry

Detection Strategies

• Monitor web application logs for POST requests to the password change endpoint with missing or empty password parameters
• Implement database integrity checks to detect accounts with empty or null password fields
• Deploy web application firewall (WAF) rules to block password change requests lacking valid password values
• Use SentinelOne Singularity Platform to detect anomalous authentication patterns and potential account compromise

Monitoring Recommendations

• Enable detailed logging on authentication and password change endpoints
• Configure alerts for any password change operations that result in empty credential storage
• Regularly audit user account database for password field integrity
• Monitor for mass password change attempts that could indicate automated exploitation

How to Mitigate CVE-2025-63800

Immediate Actions Required

• Audit all user accounts in the OSPOS database to identify any with empty or null passwords
• Reset passwords for any affected accounts immediately
• Implement temporary access controls or additional authentication layers for administrative accounts
• Review application logs for evidence of prior exploitation attempts

Patch Information

Users should monitor the OpenSourcePOS GitHub Repository for security updates and patches addressing this vulnerability. Additionally, security researchers have documented this vulnerability in detail at the CVE-2025-63800 Research Repository. Until an official patch is released, organizations should implement the workarounds described below.

Workarounds

• Implement a reverse proxy or WAF rule to reject password change requests with empty password parameters
• Add custom server-side validation to the password change endpoint to enforce minimum password length requirements
• Restrict access to the password change functionality through network segmentation or additional authentication controls
• Consider disabling the password change feature entirely until a patch is available

# Example WAF rule to block empty password submissions
# Apache ModSecurity configuration
SecRule REQUEST_URI "@contains /password/change" \
    "id:100001,phase:2,deny,status:403,msg:'Empty password blocked',\
    chain"
SecRule ARGS:password "@eq ''" "t:none"