CVE-2026-27574

Comprehensive Technical Analysis of CVE-2026-27574

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2026-27574 CVSS Score: 9.9

The vulnerability in OneUptime, a monitoring and management solution for online services, allows for a trivial sandbox escape via the Node.js node:vm module. This module is explicitly documented as not being a security mechanism, yet it is used to execute user-supplied code. The vulnerability enables an attacker to gain full access to the underlying process, leading to a full cluster compromise.

Severity Evaluation:

• Critical: The CVSS score of 9.9 indicates a critical vulnerability. The ease of exploitation, combined with the potential for full cluster compromise, makes this a high-priority issue.
• Impact: Full cluster compromise, including access to sensitive credentials and network resources.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Unauthenticated Access: The vulnerability can be exploited by any anonymous user due to open registration being enabled by default.
• Low Privilege Role: Even users with the lowest role (ProjectMember) can create monitors, which can be exploited to achieve full cluster compromise.

Exploitation Methods:

• Code Execution: An attacker can supply malicious JavaScript code through the custom JavaScript monitor feature.
• Sandbox Escape: Using a well-known one-liner, the attacker can escape the sandbox and gain full access to the underlying process.
• Credential Exfiltration: The attacker can access environment variables holding sensitive credentials (ONEUPTIME_SECRET, DATABASE_PASSWORD, REDIS_PASSWORD, CLICKHOUSE_PASSWORD).

3. Affected Systems and Software Versions

Affected Versions:

• OneUptime versions 9.5.13 and below.

Fixed Version:

• The issue has been resolved in version 10.0.5.

4. Recommended Mitigation Strategies

Immediate Actions:

• Upgrade: Immediately upgrade to OneUptime version 10.0.5 or later.
• Disable Open Registration: Temporarily disable open registration to limit the attack surface.
• Restrict Monitor Creation: Limit the ability to create monitors to trusted users only.

Long-Term Strategies:

• Code Review: Conduct a thorough code review to ensure that user-supplied code is handled securely.
• Security Audits: Regularly perform security audits and penetration testing.
• Least Privilege: Implement the principle of least privilege for all roles and permissions.

5. Impact on Cybersecurity Landscape

Broader Implications:

• Supply Chain Risk: Vulnerabilities in monitoring solutions can have cascading effects, impacting the security of all monitored services.
• Credential Management: Highlights the importance of secure credential management and the risks associated with exposing sensitive information in environment variables.
• User Trust: Undermines trust in monitoring solutions, emphasizing the need for robust security practices in all software development.

6. Technical Details for Security Professionals

Technical Overview:

• Node.js node:vm Module: This module is used to execute JavaScript code in a sandboxed environment. However, it is not designed to be a security boundary and can be easily escaped.
• Environment Variables: The probe runs with host networking and holds all cluster credentials in its environment variables, making it a high-value target.
• Exploitation Steps:
  1. Create Monitor: An attacker creates a custom JavaScript monitor.
  2. Inject Code: The attacker injects a well-known one-liner to escape the sandbox.
  3. Access Credentials: The attacker gains access to sensitive environment variables.
  4. Cluster Compromise: The attacker uses the obtained credentials to compromise the entire cluster.

Mitigation Implementation:

• Code Sanitization: Ensure that all user-supplied code is properly sanitized and executed in a secure context.
• Environment Isolation: Isolate environment variables and sensitive data from user-accessible processes.
• Role-Based Access Control (RBAC): Implement strict RBAC to limit the actions that low-privilege users can perform.

Conclusion: CVE-2026-27574 represents a critical vulnerability in OneUptime that can lead to full cluster compromise. Immediate mitigation through upgrading to the patched version and implementing strict access controls is essential. This incident underscores the importance of secure coding practices and the need for continuous security monitoring and auditing in software development.