If your Go applications connect to Snowflake’s data platform using the popular gosnowflake driver, there is a recent critical security advisory you need to know about: CVE-2025-46327. This vulnerability could allow attackers on Linux or macOS systems to gain unauthorized control over the logging configuration files, causing information leaks or log tampering—potentially allowing deeper exploitation.

Let’s break down what happened, how the security hole works, give technical details with code snippets, and explain how to stay safe.

What is CVE-2025-46327?

- Weakness Type: Time-of-Check to Time-of-Use (TOCTOU) Race Condition
- Affected Package: gosnowflake (Snowflake Golang driver)

What Is “Easy Logging” in gosnowflake?

The “Easy Logging” feature allows you to specify external files for driver logging (log level, output location, etc.), making it simpler to control what is logged from Snowflake driver activity.

How the Vulnerability Works

To keep logging configurations secure, gosnowflake tried to ensure that the log config file is only writable by its owner. Here’s the process:

1. Before reading the config, gosnowflake checks the file permissions (who owns it, who can write it).

If the check passes, it reads the file and applies the settings.

The problem? On Linux and macOS, an attacker with local access could—between the check and the use—replace the configuration file (for example, using a symbolic link or race-based overwrite). This is called a Time-of-Check to Time-of-Use (“TOCTOU”) bug, because the conditions may change after the check but before the file is actually used.

Worse, the driver did not verify that the current user equals the file owner, so a carefully timed exploit lets another user gain control of logging, which could then be twisted for privilege escalation, information leaks, or poisoning log files to hide other attacks.

A Simple Exploit Scenario

Let’s say /tmp/logconf.yaml is user1’s configuration file and is properly set for owner-only access. But, in the gap between gosnowflake checking and loading the file, user2 swaps in a symlink or replaces the file:

# Attacker (user2) waits for just the right moment...
ln -sf /tmp/evil.yaml /tmp/logconf.yaml

Then the driver, running as user1, loads /tmp/evil.yaml instead — all while thinking permissions are safe! Now, attacker controls logs or directs sensitive logs to a location they can snoop.

The problematic pattern looks like this (simplified Go snippet)

info, err := os.Stat(configFilePath)
if err != nil {
    return err
}
// Check file mode/ownership
if info.Mode().Perm() != 060 {
    return errors.New("wrong permissions!")
}
// <------- Race window starts here ------->
conf, err := ioutil.ReadFile(configFilePath)
// <------- Attacker swaps file here ------>
if err != nil {
    return err
}
// Parse conf...

What’s missing: The code checks permissions and ownership, but between those lines, an attacker can swap the file.

How Can Attackers Abuse This?

- Change log level: Turn off logging to hide evidence, or turn on verbose logging to cause performance hits or information exposure.
- Change log destination: Write logs to locations the attacker controls (read sensitive info), or to nonstandard places to avoid audits.
- Malicious configuration: Potentially inject invalid configs leading to further denial-of-service, or pave way for further privilege escalation.

Official Patch

The gosnowflake team patched this in version 1.13.3. The fix closes the race window and also makes sure the user running the driver matches the file owner.

References and Further Reading

- GitHub Advisory: CVE-2025-46327 *(Insert official advisory link when available)*
- gosnowflake GitHub Repository
- Release Notes for v1.13.3
- What is a TOCTOU race? (CWE-367)
- Full Patch Diff

How to Protect Your Applications

1. Upgrade gosnowflake: Use go get github.com/snowflakedb/gosnowflake@v1.13.3 or higher.
2. Audit for Easy Logging: If you depend on configuration files external to your code, check they’re non-world-writable, not symlinks, and owned only by their intended user.

Understand Logging Risks: Audit your logs for security, not just operational, risk.

Summary:
CVE-2025-46327 shows that even harmless-looking features like logging can open deep security gaps. If you use gosnowflake with Easy Logging on Linux/macOS, upgrade now. For more details, check the official release notes and CVE tracker.

Timeline

Published on: 04/28/2025 23:15:44 UTC
Last modified on: 05/09/2025 19:38:11 UTC