CVE-2020-2001 in PAN-OS
Summary
by MITRE
An external control of path and data vulnerability in the Palo Alto Networks PAN-OS Panorama XSLT processing logic that allows an unauthenticated user with network access to PAN-OS management interface to write attacker supplied file on the system and elevate privileges. This issue affects: All PAN-OS 7.1 Panorama versions; PAN-OS 8.0 versions earlier than 8.0.21 on Panorama; PAN-OS 8.1 versions earlier than 8.1.12 on Panorama; PAN-OS 9.0 versions earlier than 9.0.6 on Panorama.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability described in CVE-2020-2001 represents a critical external control of path and data flaw within Palo Alto Networks PAN-OS Panorama's XSLT processing functionality. This weakness stems from insufficient input validation and sanitization mechanisms that allow malicious actors to manipulate file paths and data during XSLT transformations. The vulnerability exists in the management interface processing logic where user-supplied data is directly incorporated into file system operations without proper authorization checks or path validation. The flaw specifically impacts multiple versions of PAN-OS Panorama across different release branches, creating a widespread attack surface that affects organizations relying on these security appliances for network protection.
The technical exploitation of this vulnerability occurs through manipulation of XSLT processing parameters that control file system operations within the Panorama management interface. An unauthenticated attacker with network access to the management interface can craft malicious XSLT transformations that bypass normal file system access controls and write arbitrary files to the system. This initial compromise allows for privilege escalation and persistent access to the affected device. The vulnerability demonstrates characteristics consistent with CWE-73, which describes "External Control of File Name or Path" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: XSLT Transformation," indicating that attackers can leverage this flaw to execute arbitrary code and gain elevated privileges within the network security infrastructure.
The operational impact of this vulnerability extends beyond simple unauthorized file creation to encompass complete system compromise and potential network infiltration. Organizations using affected PAN-OS Panorama versions face significant risk as attackers can leverage this vulnerability to establish persistent backdoors, modify security policies, or exfiltrate sensitive network information. The attack vector requires only network access to the management interface, making it particularly dangerous as it can be exploited from external networks without requiring prior authentication. This vulnerability undermines the fundamental security posture of Palo Alto Networks devices, as it allows attackers to bypass authentication mechanisms and directly manipulate the underlying operating system through legitimate management interfaces.
Mitigation strategies for CVE-2020-2001 focus on immediate version upgrades to patched releases that address the XSLT processing logic flaws. Organizations should prioritize upgrading all affected PAN-OS Panorama versions to their respective patched releases, specifically targeting PAN-OS 8.0.21, 8.1.12, and 9.0.6 or later versions. Network segmentation and access control measures should be implemented to restrict access to management interfaces, limiting exposure to unauthorized users. Additional protective measures include disabling unnecessary XSLT processing capabilities when not required, implementing strict network access controls through firewall rules, and monitoring for suspicious file system activities. Security teams should also conduct comprehensive vulnerability assessments of their PAN-OS deployments to identify any potential exploitation attempts and establish robust incident response procedures for handling such compromises. The vulnerability highlights the importance of secure coding practices in network security appliances and the critical need for regular security updates to protect against emerging threats in the cybersecurity landscape.