CVE-2025-27496: Snowflake JDBC Information Disclosure Flaw

CVE-2025-27496 Overview

CVE-2025-27496 is an information disclosure vulnerability in the Snowflake JDBC driver affecting versions 3.0.13 through 3.23.0. When the logging level is set to DEBUG, the driver logs the client-side encryption master key of the target stage during the execution of GET/PUT commands to local log files. This sensitive cryptographic material exposure could potentially be leveraged by attackers with local access to the system to compromise encrypted data transfers.

Critical Impact

Client-side encryption master keys are logged in plaintext when DEBUG logging is enabled, potentially exposing sensitive cryptographic material to unauthorized local users.

Affected Products

• Snowflake JDBC Driver versions 3.0.13 through 3.23.0
• Applications using the affected Snowflake JDBC driver for data stage operations
• Systems with DEBUG logging enabled for Snowflake JDBC connections

Discovery Timeline

• 2025-03-13 - CVE-2025-27496 published to NVD
• 2025-08-22 - Last updated in NVD database

Technical Details for CVE-2025-27496

Vulnerability Analysis

This vulnerability is classified as CWE-532 (Insertion of Sensitive Information into Log File). The Snowflake JDBC driver failed to properly sanitize sensitive encryption material from log output when operating in DEBUG mode. During GET and PUT file transfer operations, the driver would write the client-side encryption master key in plaintext to local log files, creating an unintended information disclosure vector.

The vulnerability requires local access to exploit, as the encryption keys are only logged locally and are not transmitted to Snowflake servers. While the key alone does not grant access to sensitive data without additional authorization, it represents a significant weakening of the encryption layer protecting staged data transfers.

Root Cause

The root cause stems from insufficient log sanitization in the SnowflakeFileTransferAgent.java component. The driver's logging mechanism did not filter out sensitive encryption material from the encryptionMaterial object before writing to DEBUG logs. The fix introduces the SecretDetector utility class to identify and redact sensitive information patterns before log output.

Attack Vector

This vulnerability has a local attack vector requiring an attacker to have access to the system where the Snowflake JDBC driver logs are stored. The exploitation scenario involves:

1. An application using the vulnerable Snowflake JDBC driver with DEBUG logging enabled
2. File transfer operations (GET/PUT commands) being executed against a Snowflake stage
3. An attacker with local file system access reading the log files
4. Extraction of the client-side encryption master key from log entries

The patch introduces pattern matching to detect and sanitize encryption material from logs:

// Security patch adding SecretDetector import for log sanitization
import net.snowflake.client.log.ArgSupplier;
import net.snowflake.client.log.SFLogger;
import net.snowflake.client.log.SFLoggerFactory;
+import net.snowflake.client.util.SecretDetector;
import net.snowflake.common.core.FileCompressionType;
import net.snowflake.common.core.RemoteStoreFileEncryptionMaterial;
import net.snowflake.common.core.SqlState;

Source: GitHub Commit

The SecretDetector class was enhanced with a new pattern to identify and redact encryption material:

// Pattern added to detect and redact encryption material in logs
          "(token|assertion content)" + "(['\"\s:=]+)" + "([a-z0-9=/_\-+]{8,})",
          Pattern.CASE_INSENSITIVE);

+  private static final Pattern ENCRYPTION_MATERIAL_PATTERN =
+      Pattern.compile("\"encryptionMaterial\"\\s*:\\s*\\{.*?\\}", Pattern.CASE_INSENSITIVE);

  // only attempt to find secrets in its leading 100Kb SNOW-30961
  private static final int MAX_LENGTH = 100 * 1000;

Source: GitHub Commit

Detection Methods for CVE-2025-27496

Indicators of Compromise

• Presence of encryptionMaterial JSON objects containing queryStageMasterKey in application log files
• DEBUG-level log entries from Snowflake JDBC driver containing encryption key patterns
• Unusual file access patterns to application log directories containing Snowflake JDBC logs

Detection Strategies

• Scan existing log files for patterns matching "encryptionMaterial"\s*:\s*\{ to identify exposed keys
• Audit logging configurations to identify applications with DEBUG logging enabled for Snowflake JDBC
• Monitor file access events on directories containing Snowflake JDBC application logs
• Review application dependencies to identify usage of vulnerable driver versions (3.0.13 through 3.23.0)

Monitoring Recommendations

• Implement log file integrity monitoring for applications using Snowflake JDBC driver
• Configure alerts for unauthorized access attempts to application log directories
• Enable file access auditing on systems running Snowflake-connected applications
• Regularly scan log files for sensitive data patterns using DLP tools

How to Mitigate CVE-2025-27496

Immediate Actions Required

• Upgrade Snowflake JDBC driver to version 3.23.1 or later immediately
• Review and rotate any encryption keys that may have been logged in DEBUG mode
• Audit existing log files for exposed encryption material and securely delete affected logs
• Disable DEBUG logging in production environments if upgrade cannot be performed immediately

Patch Information

Snowflake has released version 3.23.1 of the JDBC driver which resolves this vulnerability. The patch (commit ef81582ce2f1dbc3c8794a696c94f4fe65fad507) introduces the SecretDetector utility to sanitize sensitive encryption information before logging. Organizations should update their dependencies to the patched version as documented in the GitHub Security Advisory.

Workarounds

• Set logging level to INFO or higher (avoid DEBUG) in production environments until upgrade is complete
• Implement strict file system permissions on log directories to limit access to authorized personnel only
• Configure log rotation with secure deletion to minimize exposure window of potentially sensitive logs
• Monitor log files for sensitive patterns and implement automated redaction where possible

# Configuration example - Set logging level to avoid DEBUG in log4j
# log4j.properties configuration
log4j.logger.net.snowflake=INFO

# Or in Java system properties
-Dnet.snowflake.jdbc.logLevel=INFO