CVE-2020-2009 in PAN-OS
Summary
by MITRE
An external control of filename vulnerability in the SD WAN component of Palo Alto Networks PAN-OS Panorama allows an authenticated administrator to send a request that results in the creation and write of an arbitrary file on all firewalls managed by the Panorama. In some cases this results in arbitrary code execution with root permissions. This issue affects: All versions of PAN-OS 7.1; PAN-OS 8.1 versions earlier than 8.1.14; PAN-OS 9.0 versions earlier than 9.0.7.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability identified as CVE-2020-2009 represents a critical external control of filename flaw within the software-defined wide area network component of Palo Alto Networks PAN-OS Panorama platform. This security weakness stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied filename data during administrative operations. The flaw specifically manifests when authenticated administrators interact with the SD WAN management functionality, creating a pathway for malicious actors to manipulate file creation processes across all managed firewalls within the Panorama environment.
This vulnerability operates under the Common Weakness Enumeration framework as CWE-22, specifically categorized as "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')". The technical implementation flaw occurs in the filename handling logic where the system accepts user-controllable input without adequate sanitization or validation checks. When an authenticated administrator submits a specially crafted request through the Panorama interface, the system processes the malformed filename parameter and executes file creation operations without proper path restrictions or access controls. The vulnerability exploits the trust relationship between the Panorama management server and its managed firewalls, allowing arbitrary file creation at critical system locations.
The operational impact of this vulnerability extends beyond simple unauthorized file creation to encompass full system compromise capabilities. Attackers can leverage this weakness to establish persistent backdoor access by creating malicious files in system directories, potentially executing arbitrary code with root privileges on affected firewalls. The scope of exploitation covers all versions of PAN-OS 7.1 and specific earlier versions of PAN-OS 8.1 and 9.0, making it particularly concerning for organizations maintaining legacy systems. The vulnerability's exploitation requires only authenticated administrative access, significantly reducing the attack surface compared to remote exploits, yet the privilege escalation potential makes it extremely dangerous within compromised environments.
Organizations affected by CVE-2020-2009 should immediately implement mitigations including patching to supported versions, such as PAN-OS 8.1.14 and 9.0.7, which contain the necessary fixes for the filename validation logic. Network segmentation and access control measures should be enhanced to limit administrative access to Panorama systems, while monitoring should be implemented to detect anomalous file creation patterns. The ATT&CK framework categorizes this vulnerability under T1059 for Command and Scripting Interpreter and T1078 for Valid Accounts, as exploitation requires legitimate administrative credentials but results in unauthorized code execution. Additional defensive measures include implementing strict input validation policies, conducting regular security assessments, and establishing robust change management procedures to prevent unauthorized modifications to critical system files.