CVE-2020-37005 Overview
TimeClock Software 1.01 contains an authenticated time-based SQL injection vulnerability that allows attackers to enumerate valid usernames by manipulating the notes parameter. Attackers can inject conditional time delays in the add_entry.php endpoint to determine user existence by measuring response time differences. This SQL injection vulnerability (CWE-89) can be exploited over the network by authenticated users to extract sensitive information from the underlying database.
Critical Impact
Authenticated attackers can enumerate valid usernames and potentially extract sensitive database contents through time-based SQL injection, compromising user privacy and enabling further targeted attacks.
Affected Products
- TimeClock Software 1.01
Discovery Timeline
- 2026-01-29 - CVE CVE-2020-37005 published to NVD
- 2026-01-29 - Last updated in NVD database
Technical Details for CVE-2020-37005
Vulnerability Analysis
This vulnerability is a classic time-based blind SQL injection affecting the add_entry.php endpoint in TimeClock Software 1.01. The application fails to properly sanitize user-supplied input in the notes parameter before incorporating it into SQL queries. By exploiting this flaw, an authenticated attacker can inject SQL statements that include conditional time delays, such as SLEEP() or BENCHMARK() functions in MySQL environments.
The time-based nature of this attack means that even when the application does not return direct error messages or query results, attackers can infer information by measuring the response time of their requests. If a condition is true, the injected delay executes, causing a measurable lag in the server's response. This technique enables attackers to systematically enumerate valid usernames character by character.
Root Cause
The root cause of this vulnerability is improper input validation and lack of parameterized queries in the add_entry.php file. The notes parameter is directly concatenated into SQL statements without sanitization, allowing attackers to break out of the intended query context and inject arbitrary SQL commands. This represents a failure to follow secure coding practices for database interactions.
Attack Vector
The attack vector is network-based and requires authenticated access to the application. An attacker with valid credentials can submit specially crafted requests to the add_entry.php endpoint, manipulating the notes parameter to include time-based SQL injection payloads. By observing response time differences, the attacker can:
- Confirm the existence of the SQL injection vulnerability
- Enumerate valid usernames in the system
- Potentially extract additional sensitive data from the database
- Map the database schema for further exploitation
The vulnerability requires low privilege access and no user interaction, making it relatively easy to exploit once authentication is obtained. Technical details and exploitation techniques are documented in the Exploit-DB #48874 entry and the VulnCheck SQL Injection Advisory.
Detection Methods for CVE-2020-37005
Indicators of Compromise
- Unusual patterns in web server logs showing repeated requests to add_entry.php with varying notes parameter values
- Requests containing SQL-specific keywords such as SLEEP, BENCHMARK, WAITFOR, or IF statements in the notes parameter
- Abnormal response time patterns indicating successful time-based injection attempts
- Multiple sequential requests from the same source with incrementally modified injection payloads
Detection Strategies
- Implement web application firewall (WAF) rules to detect and block SQL injection patterns in HTTP parameters
- Configure database query logging to identify anomalous queries with time-delay functions
- Deploy intrusion detection systems (IDS) with signatures for common SQL injection attack patterns
- Monitor application response times for statistical anomalies that may indicate exploitation attempts
Monitoring Recommendations
- Enable detailed logging on the web server and database server to capture suspicious activity
- Set up alerts for requests to add_entry.php containing SQL injection indicators
- Implement rate limiting on authentication endpoints and form submissions to slow enumeration attacks
- Review access logs regularly for patterns consistent with automated SQL injection tools
How to Mitigate CVE-2020-37005
Immediate Actions Required
- Restrict access to the TimeClock Software application to trusted networks only until a patch is available
- Implement a web application firewall (WAF) with SQL injection protection rules
- Review and limit user account privileges to minimize the impact of compromised credentials
- Audit existing user accounts and monitor for signs of unauthorized access
Patch Information
No official vendor patch information is available for this vulnerability. The TimeClock Software product appears to be discontinued based on archived vendor information. Organizations using this software should consider migrating to a supported alternative solution. For additional technical details, refer to the VulnCheck SQL Injection Advisory.
Workarounds
- Deploy a web application firewall (WAF) configured to block SQL injection patterns in all input parameters
- Implement network-level access controls to restrict application access to trusted IP addresses
- If source code is available, modify the add_entry.php file to use parameterized queries or prepared statements
- Consider disabling or removing the vulnerable endpoint if it is not essential for business operations
- Migrate to a modern, actively maintained time tracking solution with proper security controls
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
