CVE-2018-25202: SAT CFDI 3.3 SQL Injection Vulnerability

CVE-2018-25202 Overview

SAT CFDI 3.3 contains an SQL injection vulnerability that allows attackers to manipulate database queries by injecting SQL code through the id parameter in the signIn endpoint. Attackers can submit POST requests with boolean-based blind, stacked queries, or time-based blind SQL injection payloads to extract sensitive data or compromise the application.

Critical Impact

Unauthenticated attackers can exploit this SQL injection vulnerability to extract sensitive data from the database, potentially including user credentials, financial records, and other confidential information processed by the CFDI verification system.

Affected Products

• SAT CFDI 3.3 (Verification and Validation System)

Discovery Timeline

• 2026-03-26 - CVE CVE-2018-25202 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2018-25202

Vulnerability Analysis

This vulnerability is classified as CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. The SAT CFDI 3.3 application fails to properly sanitize user-supplied input in the id parameter of the signIn endpoint before incorporating it into SQL queries.

The network-accessible attack surface allows remote exploitation without requiring any authentication or user interaction. An attacker can leverage multiple SQL injection techniques including boolean-based blind injection, time-based blind injection, and stacked queries to interact with the underlying database system.

Root Cause

The root cause of this vulnerability lies in the improper handling of user input within the authentication mechanism. The signIn endpoint directly concatenates or interpolates the id parameter into SQL queries without proper input validation, parameterization, or use of prepared statements. This allows malicious SQL syntax injected through the parameter to be interpreted and executed by the database engine.

Attack Vector

The vulnerability is exploitable over the network via POST requests to the signIn endpoint. An attacker constructs malicious payloads within the id parameter that alter the intended SQL query logic. The three primary exploitation techniques identified are:

Boolean-based Blind SQL Injection: The attacker injects conditional statements that cause different application responses based on true/false conditions, allowing data extraction one bit at a time.

Time-based Blind SQL Injection: The attacker uses SQL delay functions (such as SLEEP() or WAITFOR DELAY) to infer information based on response timing differences.

Stacked Queries: The attacker terminates the original query and appends additional malicious SQL statements, potentially allowing data modification, deletion, or privilege escalation within the database.

For detailed technical information and proof-of-concept examples, refer to the Exploit-DB #44726 and VulnCheck Advisory.

Detection Methods for CVE-2018-25202

Indicators of Compromise

• Unusual SQL syntax patterns in HTTP POST request bodies targeting the signIn endpoint
• Presence of SQL keywords such as UNION, SELECT, SLEEP, WAITFOR, or -- in the id parameter
• Abnormal database query execution times indicating time-based injection attempts
• Database error messages exposed in application responses
• Unexpected database queries or data access patterns in database logs

Detection Strategies

• Deploy web application firewall (WAF) rules to detect and block SQL injection payloads in POST requests
• Implement application-level logging to capture all requests to the signIn endpoint with full parameter values
• Configure database monitoring to alert on anomalous query patterns or excessive failed queries
• Use intrusion detection systems (IDS) with SQL injection signature detection capabilities

Monitoring Recommendations

• Monitor web server access logs for repeated POST requests to the authentication endpoint with varying id parameter values
• Set up alerts for database query execution times exceeding normal thresholds
• Track and alert on database error rates that may indicate injection probing
• Review authentication logs for patterns suggesting automated exploitation attempts

How to Mitigate CVE-2018-25202

Immediate Actions Required

• Remove or restrict access to the vulnerable SAT CFDI 3.3 application from untrusted networks
• Implement a web application firewall with SQL injection detection rules as an interim protective measure
• Review database permissions to ensure the application uses least-privilege database accounts
• Enable verbose logging on the signIn endpoint to detect ongoing exploitation attempts

Patch Information

No vendor patch information is currently available in the CVE data. Organizations using SAT CFDI 3.3 should contact the vendor for remediation guidance or consider migrating to a more secure alternative. Technical details regarding this vulnerability can be found in the VulnCheck Advisory and WeCodex Security Item.

Workarounds

• Place the application behind a reverse proxy with SQL injection filtering capabilities
• Implement input validation at the network perimeter to reject requests containing SQL metacharacters
• Restrict network access to the application to trusted IP ranges only
• If source code access is available, implement parameterized queries or prepared statements for all database interactions

# Example WAF rule for ModSecurity to block SQL injection attempts
SecRule ARGS:id "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in signIn endpoint',\
    tag:'CVE-2018-25202'"