CVE-2026-3065: Hummerrisk RCE Vulnerability

CVE-2026-3065 Overview

A command injection vulnerability has been identified in HummerRisk, an open-source cloud security platform. The vulnerability affects the function CommandUtils.commonExecCmdWithResult within the file CloudTaskService.java of the Cloud Task Dry-run component. By manipulating the fileName argument, an authenticated attacker can inject arbitrary operating system commands, enabling remote code execution on affected systems.

Critical Impact

Authenticated attackers can achieve remote command execution by exploiting improper input handling in the Cloud Task Dry-run component, potentially compromising the underlying server infrastructure.

Affected Products

• HummerRisk versions up to and including 1.5.0
• Systems utilizing the Cloud Task Dry-run functionality
• Deployments with network-accessible HummerRisk instances

Discovery Timeline

• 2026-02-24 - CVE-2026-3065 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-3065

Vulnerability Analysis

This vulnerability is classified as a command injection flaw (CWE-77) and more broadly as an injection vulnerability (CWE-74). The vulnerable component resides in the CloudTaskService.java file, specifically within the CommandUtils.commonExecCmdWithResult function that processes the fileName parameter.

The application fails to properly sanitize or validate user-supplied input before incorporating it into system command execution. When the Cloud Task Dry-run feature processes a request, the fileName argument is directly passed to a command execution context without adequate input validation, allowing attackers to append or inject malicious commands.

The vulnerability requires authentication to exploit, meaning attackers must have valid credentials to access the affected functionality. However, once authenticated, the attack can be executed remotely over the network with low complexity, potentially affecting the confidentiality, integrity, and availability of the target system.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization in the CommandUtils.commonExecCmdWithResult function. The fileName parameter is concatenated or interpolated directly into a system command string without proper escaping or whitelisting of allowed characters. This allows special characters and command separators (such as ;, |, &&, or backticks) to break out of the intended command context and execute additional attacker-controlled commands.

Attack Vector

The attack vector is network-based, requiring authenticated access to the HummerRisk application. An attacker with valid credentials can exploit this vulnerability through the Cloud Task Dry-run interface by submitting a crafted fileName parameter containing command injection payloads.

The exploitation flow involves:

1. Authenticating to the HummerRisk application with valid credentials
2. Accessing the Cloud Task Dry-run functionality
3. Submitting a request with a maliciously crafted fileName parameter containing shell metacharacters and injected commands
4. The vulnerable CommandUtils.commonExecCmdWithResult function processes the input without proper sanitization
5. The injected commands execute with the privileges of the HummerRisk application

For technical details regarding exploitation, refer to the GitHub Issue Discussion which contains additional information about this vulnerability.

Detection Methods for CVE-2026-3065

Indicators of Compromise

• Unusual command execution patterns originating from the HummerRisk application process
• Unexpected child processes spawned by the HummerRisk service
• Anomalous network connections from the HummerRisk server to external hosts
• Log entries showing malformed or suspicious fileName parameters in Cloud Task requests

Detection Strategies

• Monitor system call activity from the HummerRisk process for unexpected command execution
• Implement application-layer logging to capture all Cloud Task Dry-run requests with full parameter details
• Deploy intrusion detection rules to identify common command injection patterns in HTTP traffic to HummerRisk endpoints
• Review authentication logs for unusual access patterns to the Cloud Task functionality

Monitoring Recommendations

• Enable verbose logging for the HummerRisk application and retain logs for forensic analysis
• Configure alerting for process execution chains that deviate from normal HummerRisk behavior
• Monitor for file system changes in sensitive directories following Cloud Task operations
• Implement network segmentation to limit potential lateral movement if exploitation occurs

How to Mitigate CVE-2026-3065

Immediate Actions Required

• Restrict network access to HummerRisk instances to trusted IP ranges only
• Review and audit user accounts with access to the Cloud Task Dry-run functionality
• Implement additional authentication controls such as multi-factor authentication
• Consider temporarily disabling the Cloud Task Dry-run feature if not critical to operations

Patch Information

At the time of publication, the vendor (HummerRisk) has not responded to disclosure communications regarding this vulnerability. No official patch is currently available. Organizations should monitor the HummerRisk GitHub repository and vendor channels for security updates. Additional vulnerability details are available through VulDB #347416.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules to block common command injection patterns targeting the affected endpoint
• Implement input validation at the network perimeter to filter requests containing shell metacharacters in the fileName parameter
• Restrict access to the Cloud Task Dry-run functionality using network segmentation or application-level access controls
• Consider running HummerRisk in a containerized environment with restricted system capabilities to limit the impact of successful exploitation

# Example WAF rule to block common command injection patterns
# Add to your reverse proxy or WAF configuration
# Block requests containing shell metacharacters in fileName parameter
SecRule ARGS:fileName "@rx [;|&`$(){}<>]" "id:1001,phase:2,deny,status:403,log,msg:'Potential command injection in fileName parameter'"