CVE-2026-28446

Comprehensive Technical Analysis of CVE-2026-28446

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2026-28446 CVSS Score: 9.8

The vulnerability in OpenClaw versions prior to 2026.2.1, specifically within the voice-call extension, allows for an authentication bypass due to flawed inbound allowlist policy validation. The system accepts empty caller IDs and uses suffix-based matching instead of strict equality, enabling remote attackers to bypass access controls.

Severity Evaluation:

• CVSS Score: 9.8 (Critical)
• Impact: High
• Exploitability: High

The high CVSS score indicates a critical vulnerability that can be easily exploited by remote attackers, leading to significant security risks.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Empty Caller IDs: Attackers can place calls with missing caller IDs, bypassing the inbound allowlist policy.
2. Suffix-Based Matching: Attackers can use numbers ending with allowlisted digits to exploit the suffix-based matching mechanism.

Exploitation Methods:

• Remote Exploitation: Attackers can remotely place calls with crafted caller IDs to bypass the allowlist and reach the voice-call agent.
• Tool Execution: Once access is gained, attackers can execute tools within the voice-call agent, potentially leading to further compromise.

3. Affected Systems and Software Versions

Affected Systems:

• OpenClaw versions prior to 2026.2.1 with the voice-call extension installed and enabled.

Software Versions:

• All versions of OpenClaw before 2026.2.1.

4. Recommended Mitigation Strategies

Immediate Mitigation:

1. Upgrade Software: Upgrade to OpenClaw version 2026.2.1 or later, which includes the necessary patches.
2. Disable Voice-Call Extension: Temporarily disable the voice-call extension if an immediate upgrade is not possible.
3. Strict Caller ID Validation: Implement strict caller ID validation rules to ensure only valid and complete caller IDs are accepted.

Long-Term Mitigation:

1. Regular Patch Management: Implement a robust patch management program to ensure timely updates and patches.
2. Security Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate similar issues.
3. Access Controls: Enhance access control mechanisms to include multi-factor authentication and strict validation policies.

5. Impact on Cybersecurity Landscape

Immediate Impact:

• Increased Risk: Organizations using affected versions of OpenClaw are at high risk of unauthorized access and potential data breaches.
• Operational Disruption: Exploitation can lead to operational disruptions and potential financial losses.

Long-Term Impact:

• Reputation Damage: Organizations may face reputational damage if exploited.
• Regulatory Compliance: Non-compliance with regulatory requirements due to security breaches.

6. Technical Details for Security Professionals

Vulnerability Details:

• Root Cause: The vulnerability stems from the inbound allowlist policy validation logic that accepts empty caller IDs and uses suffix-based matching.
• Technical Flaw: The flawed logic allows for bypassing access controls, enabling remote attackers to reach the voice-call agent.

Exploitation Steps:

1. Crafted Caller IDs: Attackers craft caller IDs with missing information or suffixes that match allowlisted digits.
2. Access Gain: The crafted caller IDs bypass the allowlist, granting access to the voice-call agent.
3. Tool Execution: Once access is gained, attackers can execute tools within the voice-call agent, potentially leading to further compromise.

Detection and Response:

1. Log Analysis: Monitor and analyze call logs for suspicious caller IDs or patterns.
2. Intrusion Detection: Implement intrusion detection systems (IDS) to detect and alert on anomalous call activities.
3. Incident Response: Develop and implement an incident response plan to quickly address and mitigate any detected exploitation attempts.

References:

• OpenClaw GitHub Commit
• OpenClaw Security Advisory
• VulnCheck Advisory

By addressing this vulnerability promptly and implementing robust security measures, organizations can mitigate the risks associated with CVE-2026-28446 and enhance their overall cybersecurity posture.