CVE-2026-30332: Balena Etcher Privilege Escalation Flaw

CVE-2026-30332 Overview

A Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability has been identified in Balena Etcher for Windows prior to version 2.1.4. This vulnerability allows attackers to escalate privileges and execute arbitrary code by replacing a legitimate script with a crafted payload during the flashing process.

Critical Impact

Successful exploitation of this vulnerability enables local privilege escalation and arbitrary code execution, potentially allowing attackers to gain elevated system privileges on affected Windows systems.

Affected Products

• Balena Etcher for Windows versions prior to v2.1.4

Discovery Timeline

• 2026-04-02 - CVE-2026-30332 published to NVD
• 2026-04-02 - Last updated in NVD database

Technical Details for CVE-2026-30332

Vulnerability Analysis

This vulnerability is classified as CWE-367 (Time-of-check Time-of-use Race Condition). The flaw exists in the flashing process of Balena Etcher where a race condition can be exploited between the time a script is verified and the time it is executed. During this window, an attacker with local access can replace the legitimate script with a malicious payload. Since Balena Etcher runs with elevated privileges during the flashing process, successful exploitation results in arbitrary code execution with those elevated privileges.

The attack requires local access to the system and user interaction to trigger the vulnerable code path, but the scope is changed as the attacker can impact resources beyond the vulnerable component's security scope. This can lead to complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of this vulnerability lies in the improper synchronization between security checks and resource usage within Balena Etcher's flashing process. When the application validates a script file and subsequently executes it, there exists a time gap during which the file can be modified by an attacker. The application fails to maintain an atomic operation between the verification and execution phases, creating the exploitable race condition window.

Attack Vector

The attack vector is local, requiring an attacker to have access to the target system. The exploitation involves the following steps:

1. The attacker monitors the Balena Etcher flashing process initiation
2. During the brief window between script validation and execution, the attacker replaces the legitimate script with a malicious payload
3. The application proceeds to execute the replaced script with elevated privileges
4. The attacker's payload runs with the elevated privileges of the Etcher process

This vulnerability requires precise timing and local access, making exploitation more complex but still feasible for determined attackers. Technical details and a proof-of-concept are available in the GitHub PoC Repository.

Detection Methods for CVE-2026-30332

Indicators of Compromise

• Unexpected script file modifications in the Balena Etcher installation directory during flashing operations
• Process execution anomalies with Etcher's elevated privileges
• File system activity showing rapid file replacement patterns in temporary directories used by Etcher
• Unusual child processes spawned by the Etcher application

Detection Strategies

• Monitor file system operations for suspicious file replacement patterns during Etcher execution
• Implement integrity monitoring on script files used by Balena Etcher
• Track process creation events originating from Etcher processes for unexpected executables
• Deploy endpoint detection and response (EDR) solutions to identify TOCTOU exploitation attempts

Monitoring Recommendations

• Enable detailed file system auditing on directories used by Balena Etcher
• Configure SentinelOne to alert on suspicious process chains involving the Etcher application
• Monitor for rapid file access patterns indicative of race condition exploitation
• Implement behavioral analysis to detect privilege escalation attempts following Etcher execution

How to Mitigate CVE-2026-30332

Immediate Actions Required

• Upgrade Balena Etcher for Windows to version 2.1.4 or later immediately
• Restrict local access to systems where Balena Etcher is installed
• Consider temporarily disabling or uninstalling Balena Etcher until the patch can be applied
• Monitor affected systems for signs of exploitation

Patch Information

Balena has addressed this vulnerability in Etcher version 2.1.4. Organizations should update to this version or later to remediate the vulnerability. For more information, consult the Balena Security Overview and the GitHub Issue Discussion for additional context on the fix.

Workarounds

• Implement application whitelisting to prevent unauthorized scripts from executing
• Run Balena Etcher in a isolated virtual machine environment to contain potential exploitation
• Restrict local user privileges on systems where Etcher is required
• Use file integrity monitoring tools to detect unexpected file modifications during flashing operations

# Verify installed Etcher version on Windows
# Check if version is 2.1.4 or higher
winget list --name "Etcher" | findstr /i "2.1"