CVE-2021-33583: Reiner-sct Timecard SQLi Vulnerability

CVE-2021-33583 Overview

REINER timeCard 6.05.07 contains a critical hardcoded credentials vulnerability where the application installs a Microsoft SQL Server instance with an sa (system administrator) password that is hardcoded directly in the TCServer.jar file. This vulnerability allows unauthenticated attackers with network access to the SQL Server to gain full administrative control over the database, potentially compromising sensitive time tracking data, employee information, and the underlying system.

Critical Impact

Attackers can extract the hardcoded sa password from the JAR file and gain unrestricted administrative access to the Microsoft SQL Server database, enabling data theft, manipulation, and potential lateral movement within the network.

Affected Products

• REINER timeCard version 6.05.07
• REINER-SCT timeCard installations using the bundled Microsoft SQL Server

Discovery Timeline

• 2021-09-30 - CVE-2021-33583 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2021-33583

Vulnerability Analysis

This vulnerability falls under CWE-798 (Use of Hard-coded Credentials), a severe security flaw where authentication credentials are embedded directly in application code or configuration files. The REINER timeCard application embeds the Microsoft SQL Server sa account password within the TCServer.jar file, making it trivially accessible to anyone who can read the application files or extract the JAR contents.

The sa account in Microsoft SQL Server is the built-in system administrator account with unrestricted privileges over the entire database server instance. Having a hardcoded password for this account represents a fundamental security design flaw that violates basic security principles of credential management.

Root Cause

The root cause is improper credential management during the application design and deployment process. Instead of implementing secure credential storage mechanisms such as encrypted configuration files, secure vault integration, or prompting administrators to set unique credentials during installation, the developers chose to hardcode the SQL Server administrator password directly in the Java application archive.

JAR files are simply ZIP archives containing compiled Java classes and resources. Any user with access to the installation directory can extract the contents and search for the hardcoded password using basic text search tools or Java decompilers.

Attack Vector

The attack vector is network-based and requires no prior authentication or user interaction. An attacker can exploit this vulnerability through the following attack chain:

1. Obtain access to the REINER timeCard installation files (either through file system access or by downloading the installer)
2. Extract the TCServer.jar file and decompile or search its contents for database connection strings
3. Identify the hardcoded sa password embedded in the application code
4. Connect to the Microsoft SQL Server instance over the network using the discovered credentials
5. Execute arbitrary SQL commands with full system administrator privileges

Once connected with sa credentials, an attacker can read, modify, or delete any data in the database, create new user accounts, enable xp_cmdshell for operating system command execution, or pivot to other systems in the network.

Detection Methods for CVE-2021-33583

Indicators of Compromise

• Unexpected SQL Server login attempts using the sa account from external or unauthorized IP addresses
• Unusual database queries or bulk data extraction from timeCard databases
• Failed authentication attempts followed by successful sa logins indicating credential testing
• Evidence of JAR file extraction or Java decompilation tools on systems with timeCard installed

Detection Strategies

• Monitor SQL Server authentication logs for sa account login events, especially from non-localhost sources
• Implement network monitoring to detect SQL Server traffic (default port 1433) from unexpected sources
• Deploy file integrity monitoring on the timeCard installation directory to detect unauthorized access to JAR files
• Use database activity monitoring tools to alert on sensitive operations performed by the sa account

Monitoring Recommendations

• Enable SQL Server audit logging and forward events to a centralized SIEM
• Create alerts for any sa account usage since legitimate application operations should use dedicated service accounts
• Monitor for SQL Server xp_cmdshell execution or other extended stored procedures that could indicate post-exploitation activity
• Implement network segmentation to restrict SQL Server access to authorized application servers only

How to Mitigate CVE-2021-33583

Immediate Actions Required

• Change the sa account password immediately to a strong, unique value that is not stored in any application files
• Restrict network access to the SQL Server instance using firewall rules to allow only authorized hosts
• Review SQL Server logs for signs of unauthorized access using the compromised credentials
• Contact REINER-SCT for updated software versions that address this vulnerability

Patch Information

Organizations should consult the Compass Security Advisory for detailed information about this vulnerability. Contact REINER-SCT directly for guidance on patching or upgrading to a version that implements secure credential management.

Workarounds

• Disable the sa account entirely and create a dedicated service account with minimum required privileges for the timeCard application
• Implement Windows Authentication mode instead of SQL Server mixed-mode authentication where possible
• Place the SQL Server instance on an isolated network segment with strict firewall controls
• Deploy a database firewall or SQL proxy to monitor and filter database connections
• Regularly audit SQL Server permissions and remove unnecessary administrative access

# Configuration example - Restrict SQL Server network access
# Windows Firewall rule to limit SQL Server access to specific hosts only
netsh advfirewall firewall add rule name="SQL Server Restricted" dir=in action=allow protocol=TCP localport=1433 remoteip=192.168.1.100,192.168.1.101

# Disable sa account via SQL Server Management Studio or sqlcmd
# sqlcmd -S localhost -Q "ALTER LOGIN sa DISABLE"