CVE-2025-58758: TinyEnv Information Disclosure Vulnerability

CVE-2025-58758 Overview

CVE-2025-58758 is an Insecure Default Configuration vulnerability affecting TinyEnv, a PHP environment variable loader library developed by datahihi1. The vulnerability exists in versions 1.0.1, 1.0.2, 1.0.9, and 1.0.10, where TinyEnv does not require the .env file to exist when loading environment variables. This design flaw can lead to unexpected application behavior where missing configuration is silently ignored, potentially resulting in insecure defaults or deployment misconfigurations that could expose applications to security risks.

Critical Impact

Applications using vulnerable TinyEnv versions may silently operate with insecure default configurations when the .env file is missing, potentially exposing sensitive functionality or enabling unauthorized access due to unset security parameters.

Affected Products

• TinyEnv versions 1.0.1, 1.0.2, 1.0.9, and 1.0.10
• PHP applications using affected TinyEnv versions for environment variable loading
• Datahihi1 TinyEnv library prior to version 1.0.11

Discovery Timeline

• 2025-09-09 - CVE CVE-2025-58758 published to NVD
• 2025-10-08 - Last updated in NVD database

Technical Details for CVE-2025-58758

Vulnerability Analysis

This vulnerability stems from improper error handling (CWE-703) in TinyEnv's environment loading mechanism. When an application initializes TinyEnv and calls the load() method, the library does not validate whether the .env configuration file actually exists on the filesystem. Instead of throwing an exception or returning an error state, the library silently continues execution, leaving the application to operate without the expected environment variables.

This behavior is particularly dangerous in production deployments where missing configuration could result in applications running with fallback values or null configurations. For security-critical settings such as database credentials, API keys, encryption secrets, or authentication parameters, operating without proper configuration could expose the application to unauthorized access or data breaches.

Root Cause

The root cause is the absence of file existence validation in TinyEnv's loading logic. The library was designed with an overly permissive approach that assumed the calling application would handle configuration validation externally. This violates the principle of fail-safe defaults, where security mechanisms should default to a secure state when configuration is missing or incomplete.

Attack Vector

The vulnerability is exploitable via network-based attacks where an attacker can leverage the misconfigured application state. Attack scenarios include:

1. Deployment misconfiguration exploitation: If an application is deployed without its .env file, attackers could exploit insecure default behaviors such as disabled authentication, weak encryption, or exposed debug endpoints.

2. Configuration file deletion: An attacker with limited filesystem access could delete the .env file, causing the application to restart with insecure defaults.

3. Container/orchestration attacks: In containerized environments, missing volume mounts or secrets could leave applications operating without proper security configuration.

The following code demonstrates the vulnerable usage pattern and the security patch:

// Vulnerable TinyEnv usage pattern (versions 1.0.1, 1.0.2, 1.0.9, 1.0.10)
// The library silently ignores missing .env file
<?php

require_once 'src/TinyEnv.php';
require_once 'src/helper/helpers.php';

$env = new \Datahihi1\TinyEnv\TinyEnv(__DIR__, true);
$env->load();

print_r(env('USER'));

Source: GitHub Security Patch

Example .env configuration that would be silently ignored if missing:

DB_HOST=localhost
DB_PORT=3306
DB_URL=${DB_HOST}:${DB_PORT}

USER_NAME=
USER=${USER_NAME:-guest}   # default if unset or empty
ALT_USER=${USER_NAME-guest} # default if unset only

Source: GitHub Security Patch

Detection Methods for CVE-2025-58758

Indicators of Compromise

• Applications logging errors related to undefined environment variables at runtime
• Unexpected default values appearing in application configuration or logs
• Database connection failures or authentication errors after deployment
• Missing .env files in production application directories
• Application behavior inconsistent with expected environment configuration

Detection Strategies

• Audit PHP application dependencies for TinyEnv versions 1.0.1, 1.0.2, 1.0.9, or 1.0.10 using Composer
• Implement startup validation scripts that verify .env file existence before application initialization
• Monitor application logs for patterns indicating undefined configuration variables
• Use SentinelOne's application inventory to identify systems running vulnerable TinyEnv versions

Monitoring Recommendations

• Configure alerting for applications starting without expected environment variable population
• Monitor deployment pipelines for missing configuration file artifacts
• Implement health checks that validate critical environment variables are set
• Track file integrity monitoring on .env files to detect unauthorized modifications or deletions

How to Mitigate CVE-2025-58758

Immediate Actions Required

• Upgrade TinyEnv to version 1.0.11 or later immediately across all affected applications
• Audit all PHP applications using TinyEnv to identify vulnerable installations
• Verify .env files are present and properly configured in all deployment environments
• Review application behavior to ensure no insecure defaults are currently active
• Implement pre-deployment checks that validate configuration file presence

Patch Information

The vulnerability has been fixed in TinyEnv version 1.0.11. The patch introduces proper file existence validation that prevents silent failure when the .env file is missing. All users should upgrade using Composer:

composer update datahihi1/tiny-env

For more details, see the GitHub Security Advisory GHSA-3j7m-5g4q-gfpc and the patch commit.

Workarounds

• Manually verify the existence of the .env file before initializing TinyEnv in your application code
• Implement a wrapper function that checks for file existence and throws an exception if missing
• Add deployment pipeline validation to ensure .env files are present before application startup
• Use container orchestration health checks to validate configuration completeness

# Pre-startup validation script for deployments
#!/bin/bash
# Verify .env file exists before starting PHP application

ENV_FILE="/var/www/app/.env"

if [ ! -f "$ENV_FILE" ]; then
    echo "ERROR: Configuration file $ENV_FILE not found!"
    echo "Application cannot start without environment configuration."
    exit 1
fi

echo "Configuration file validated. Starting application..."
php-fpm