CVE-2026-1479: Performance Evaluation SQLi Vulnerability

CVE-2026-1479 Overview

An out-of-band SQL injection vulnerability (OOB SQLi) has been identified in the Performance Evaluation (EDD) application developed by Gabinete Técnico de Programación. This vulnerability exists in the Id_usuario and Id_evaluacion parameters within the /evaluacion_hca_ver_auto.asp endpoint, allowing attackers to extract sensitive information from the database through external channels without the application returning the data directly. This technique bypasses traditional inline SQL injection detection methods by exfiltrating data via DNS lookups, HTTP requests, or other out-of-band communication channels.

Critical Impact

Successful exploitation allows attackers to extract sensitive database information through external channels, completely compromising the confidentiality of stored information without generating typical SQL injection response patterns.

Affected Products

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

Discovery Timeline

• 2026-01-27 - CVE CVE-2026-1479 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2026-1479

Vulnerability Analysis

This out-of-band SQL injection vulnerability (CWE-89) represents a sophisticated attack vector that differs from traditional SQL injection in its data exfiltration methodology. While conventional SQL injection relies on manipulating query responses displayed to the user, OOB SQLi leverages the database server's ability to make external network connections to transmit stolen data to an attacker-controlled server.

The vulnerability is particularly dangerous because it can bypass many traditional web application firewalls and intrusion detection systems that primarily monitor HTTP response content for signs of SQL injection. Since the exfiltrated data never appears in the application's response, these security controls may fail to detect the attack.

The affected endpoint /evaluacion_hca_ver_auto.asp processes user-supplied input through the Id_usuario and Id_evaluacion parameters without proper sanitization or parameterized queries. An attacker with network access can craft malicious SQL payloads that trigger external network requests containing sensitive database content.

Root Cause

The root cause of this vulnerability is improper input validation (CWE-89: Improper Neutralization of Special Elements used in an SQL Command). The application fails to properly sanitize or parameterize user input in the Id_usuario and Id_evaluacion parameters before incorporating them into SQL queries. This allows attackers to inject malicious SQL statements that are executed by the database server. The ASP-based application likely uses string concatenation to build SQL queries rather than using prepared statements or parameterized queries.

Attack Vector

The attack is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability remotely by sending specially crafted HTTP requests to the vulnerable endpoint /evaluacion_hca_ver_auto.asp. The injected SQL payload instructs the database server to establish outbound connections (typically via DNS queries or HTTP requests) to attacker-controlled infrastructure, encoding sensitive database content within these external communications.

The OOB technique typically involves database-specific functions such as:

• DNS exfiltration using extended stored procedures or built-in functions
• HTTP requests via database server capabilities
• SMB connections to attacker-controlled servers

This exfiltration method allows data theft even when the application provides no visible feedback from the injected queries, making it a blind exploitation technique with high impact on data confidentiality.

Detection Methods for CVE-2026-1479

Indicators of Compromise

• Unusual outbound DNS queries from database servers containing encoded data patterns or suspicious subdomains
• Unexpected HTTP/HTTPS connections originating from database server processes
• Database logs showing execution of extended stored procedures or network-related functions
• Anomalous network traffic from web application servers to external unknown destinations

Detection Strategies

• Monitor database server network activity for unexpected outbound connections, particularly DNS queries with unusually long subdomain strings
• Implement web application firewall rules to detect SQL injection patterns in the Id_usuario and Id_evaluacion parameters
• Enable detailed SQL query logging and analyze for injection patterns or unusual function calls
• Deploy network intrusion detection signatures for common OOB SQLi exfiltration techniques

Monitoring Recommendations

• Configure alerts for database servers initiating outbound network connections
• Monitor DNS query logs for encoded data patterns (Base64, hex encoding) in subdomain fields
• Review web server access logs for requests to /evaluacion_hca_ver_auto.asp with suspicious parameter values
• Implement application-level logging to capture all input values submitted to vulnerable parameters

How to Mitigate CVE-2026-1479

Immediate Actions Required

• Restrict access to the vulnerable endpoint /evaluacion_hca_ver_auto.asp until a patch is available
• Implement network egress filtering to block outbound connections from database servers to untrusted destinations
• Deploy web application firewall rules to filter SQL injection patterns in affected parameters
• Review and audit database server permissions to limit access to network-related functions

Patch Information

Consult the vendor Gabinete Técnico de Programación for official patch availability. Additional technical details are available in the INCIBE Security Notice.

Workarounds

• Implement input validation to allow only numeric values in Id_usuario and Id_evaluacion parameters
• Use parameterized queries or prepared statements to prevent SQL injection
• Block database server outbound network access at the firewall level
• Consider placing the application behind a reverse proxy with SQL injection filtering capabilities

# Configuration example - Restrict database server outbound connections (iptables)
# Block all outbound traffic from database server except to authorized destinations
iptables -A OUTPUT -m owner --uid-owner mssql -j DROP
iptables -A OUTPUT -m owner --uid-owner mysql -j DROP

# Alternative: Firewall rule to block DNS exfiltration from DB server
iptables -A OUTPUT -p udp --dport 53 -m owner --uid-owner mssql -j LOG --log-prefix "DB_DNS_EXFIL: "
iptables -A OUTPUT -p udp --dport 53 -m owner --uid-owner mssql -j DROP