CVE-2020-2018 in PAN-OS
Summary
by MITRE
An authentication bypass vulnerability in Palo Alto Networks PAN-OS Panorama proxy service allows an unauthenticated user with network access to Panorama and the knowledge of the Firewall’s serial number to register the PAN-OS firewall to register the device. After the PAN-OS device is registered, the user can further compromise the PAN-OS instances managed by Panorama. This issue affects: PAN-OS 7.1 versions earlier than 7.1.26; PAN-OS 8.0 versions earlier than 8.0.21; PAN-OS 8.1 versions earlier than 8.1.12; PAN-OS 9.0 versions earlier than 9.0.6.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability described in CVE-2020-2018 represents a critical authentication bypass flaw within the Palo Alto Networks PAN-OS Panorama proxy service that fundamentally undermines the security posture of network infrastructure. This weakness stems from insufficient validation mechanisms during the device registration process, allowing unauthorized actors to exploit a procedural gap that should have required proper authentication credentials. The vulnerability specifically targets the interaction between Panorama management systems and PAN-OS firewalls, creating a pathway for attackers to gain unauthorized access to network security controls without proper authorization. The flaw is particularly concerning because it leverages network access and knowledge of a firewall's serial number as the sole prerequisites for exploitation, making it accessible to attackers who may have already gained network reconnaissance capabilities.
The technical implementation of this vulnerability resides in the proxy service's registration mechanism, which fails to adequately verify the authenticity of registration requests. According to CWE-287, this represents an improper authentication issue where the system accepts registration requests without sufficient verification of the requester's identity. The flaw allows an unauthenticated user to register a firewall device with Panorama by simply knowing the target firewall's serial number, effectively bypassing the normal authentication requirements that should govern device management operations. This authentication bypass enables attackers to establish a foothold within the PAN-OS environment and subsequently manipulate the device registration process to gain access to additional management functions. The vulnerability affects multiple PAN-OS versions across different release lines, indicating a widespread issue that has persisted across several major releases and demonstrates the complexity of the underlying authentication mechanism.
The operational impact of this vulnerability extends far beyond simple unauthorized device registration, as it provides attackers with the ability to compromise PAN-OS instances managed by Panorama, potentially leading to complete network infrastructure takeover. Once a firewall is registered through this bypass, the attacker gains access to management interfaces that should remain protected from unauthorized access, enabling them to modify security policies, view sensitive network information, and potentially redirect traffic through malicious configurations. This vulnerability aligns with ATT&CK technique T1078.004, which covers valid accounts used for lateral movement, as the registration process effectively creates a legitimate administrative presence within the PAN-OS environment. The consequences of exploitation include potential data exfiltration, network disruption, and the ability to establish persistent access points within the organization's security infrastructure, making this vulnerability particularly dangerous for enterprise networks that rely heavily on PAN-OS for security enforcement.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to the patched versions specified in the advisory, which address the authentication bypass through proper validation of registration requests. The recommended remediation strategy involves deploying the specific PAN-OS releases that contain the security fixes for each affected version line, ensuring that the proxy service properly validates registration requests before permitting device registration. Network segmentation and access controls should be strengthened to limit exposure of Panorama management interfaces to authorized personnel only, while monitoring should be implemented to detect unauthorized registration attempts. Additionally, organizations should review their device management practices and ensure that firewall serial numbers are not easily accessible to unauthorized parties, as these numbers serve as the primary credential for exploitation of this vulnerability. The fix addresses the root cause by implementing proper authentication checks within the proxy service, ensuring that only authorized administrators can register new devices with Panorama management systems.