CVE-2026-1481: Performance Evaluation SQLi Vulnerability

CVE-2026-1481 Overview

An out-of-band SQL injection vulnerability (OOB SQLi) has been discovered in the Performance Evaluation (EDD) application developed by Gabinete Técnico de Programación. This critical vulnerability exists in the Id_usuario parameter within the /evaluacion_objetivos_anyo_sig_ver_auto.aspx endpoint. Successful exploitation could allow an attacker to extract sensitive information from the database through external channels, without the affected application returning the data directly, thereby compromising the confidentiality of stored information.

Critical Impact

Unauthenticated attackers can extract sensitive database contents through external channels without direct application response, potentially exposing confidential performance evaluation data and user credentials.

Affected Products

• Performance Evaluation (EDD) Application by Gabinete Técnico de Programación
• Quatuor Performance Evaluation System

Discovery Timeline

• 2026-01-27 - CVE-2026-1481 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2026-1481

Vulnerability Analysis

This out-of-band SQL injection vulnerability (CWE-89) allows attackers to execute arbitrary SQL queries against the backend database through indirect data exfiltration channels. Unlike traditional in-band SQL injection where results are returned in the HTTP response, OOB SQLi leverages external communication mechanisms such as DNS queries or HTTP requests to extract data. This makes the vulnerability particularly dangerous as it can bypass certain security controls and is more difficult to detect through standard application monitoring.

The vulnerable parameter Id_usuario in the performance evaluation objectives page lacks proper input validation and parameterized query handling, allowing malicious SQL payloads to be injected and executed by the database server. Attackers can craft payloads that trigger the database to make outbound connections to attacker-controlled infrastructure, carrying sensitive data in the request.

Root Cause

The root cause of this vulnerability is improper input validation and the absence of parameterized queries (prepared statements) when processing the Id_usuario parameter. User-supplied input is directly concatenated into SQL queries without sanitization, allowing attackers to break out of the intended query context and inject malicious SQL commands. The application's failure to enforce the principle of least privilege on database connections may also exacerbate the impact, potentially allowing attackers to access data beyond the immediate application scope.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests to the vulnerable endpoint /evaluacion_objetivos_anyo_sig_ver_auto.aspx with a malicious payload in the Id_usuario parameter.

The out-of-band nature of this attack means that instead of receiving data in the HTTP response, the attacker leverages database functionality to make external requests (such as DNS lookups or HTTP calls) that encode the exfiltrated data. Common techniques include using database-specific functions like xp_dirtree in MSSQL, LOAD_FILE or INTO OUTFILE in MySQL, or UTL_HTTP in Oracle to establish outbound communication channels. For detailed technical analysis, see the INCIBE CERT Notice on SQL Injection.

Detection Methods for CVE-2026-1481

Indicators of Compromise

• Unusual outbound DNS queries from database servers containing encoded data patterns or suspicious domain names
• HTTP/HTTPS connections originating from database servers to external IP addresses
• Anomalous SQL query patterns in database logs containing SQL injection payloads or database-specific OOB functions
• Increased access attempts to /evaluacion_objetivos_anyo_sig_ver_auto.aspx with malformed Id_usuario parameters

Detection Strategies

• Deploy Web Application Firewalls (WAF) with SQL injection detection rules targeting the Id_usuario parameter and common OOB SQLi patterns
• Implement database activity monitoring to detect execution of functions commonly used in OOB attacks such as xp_dirtree, UTL_HTTP, or LOAD_FILE
• Monitor egress network traffic from database servers for unusual DNS queries or HTTP connections
• Enable detailed logging on the application endpoint /evaluacion_objetivos_anyo_sig_ver_auto.aspx and analyze for injection attempts

Monitoring Recommendations

• Configure SIEM rules to alert on SQL injection patterns in web server logs, particularly targeting the Id_usuario parameter
• Establish baseline network behavior for database servers and alert on deviations, especially outbound connections
• Implement real-time database query analysis to detect anomalous query structures
• Review access logs for the Performance Evaluation application for signs of reconnaissance or exploitation attempts

How to Mitigate CVE-2026-1481

Immediate Actions Required

• Block external network access from database servers to prevent OOB data exfiltration
• Implement input validation and restrict the Id_usuario parameter to expected numeric values only
• Deploy WAF rules to block SQL injection attempts on the affected endpoint
• Consider taking the vulnerable endpoint offline until a patch is applied if the application is critical and exposed to untrusted networks

Patch Information

Organizations should contact Gabinete Técnico de Programación directly for official patch availability and guidance. In the interim, refer to the INCIBE CERT Notice on SQL Injection for the latest remediation guidance.

Workarounds

• Implement parameterized queries (prepared statements) for all database interactions involving user input
• Apply strict input validation to reject any non-numeric characters in the Id_usuario parameter
• Configure database server firewall rules to block all outbound connections, preventing OOB data exfiltration
• Apply principle of least privilege to database accounts, limiting permissions to only necessary operations
• Deploy network segmentation to isolate database servers from direct internet access

# Example: Block outbound connections from database server (Linux iptables)
# Adjust interface and IP ranges as appropriate for your environment
iptables -A OUTPUT -m owner --uid-owner mysql -j DROP
iptables -A OUTPUT -m owner --uid-owner mssql -j DROP