CVE-2020-1996 in PAN-OS
Summary
by MITRE
A missing authorization vulnerability in the management server component of PAN-OS Panorama allows a remote unauthenticated user to inject messages into the management server ms.log file. This vulnerability can be leveraged to obfuscate an ongoing attack or fabricate log entries in the ms.log file This issue affects: All versions of PAN-OS 7.1 and 8.0; PAN-OS 8.1 versions earlier than 8.1.14; PAN-OS 9.0 versions earlier than 9.0.9.
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Analysis
by VulDB Data Team • 10/17/2020
This vulnerability represents a critical authorization flaw in Palo Alto Networks Panorama management server component that enables remote unauthenticated attackers to inject malicious log entries into the ms.log file. The issue stems from insufficient access controls within the management server's message handling mechanisms, allowing unauthorized users to bypass authentication requirements and manipulate system logging data. The vulnerability specifically affects multiple major versions of PAN-OS including 7.1, 8.0, 8.1 (versions prior to 8.1.14), and 9.0 (versions prior to 9.0.9), indicating a widespread impact across the product lineage. This missing authorization control creates a significant security risk as it undermines the integrity and authenticity of system logs that are critical for security monitoring and incident response activities.
The technical exploitation of this vulnerability occurs through the management server's message injection functionality, where attackers can submit crafted messages that get logged into the ms.log file without proper authentication verification. This allows threat actors to manipulate the log data in ways that can obscure their actual activities or create false evidence of system compromise. The vulnerability's impact extends beyond simple log manipulation as it can be used to interfere with security operations by creating misleading audit trails that complicate forensic investigations. The lack of proper authorization checks means that any remote user can potentially access this functionality regardless of their authentication status, making it particularly dangerous in environments where network access controls are not properly enforced.
From an operational standpoint, this vulnerability creates significant risks for security monitoring and incident response capabilities. Security teams rely on authentic log data to detect and respond to threats, and the ability to inject false entries into the ms.log file directly undermines this foundation. Attackers could leverage this vulnerability to mask their presence by creating false log entries that appear to be legitimate system activity, thereby evading detection mechanisms that depend on log analysis. The vulnerability also affects the integrity of audit trails, which are essential for compliance requirements and security assessments. Organizations using affected PAN-OS versions face potential exposure to sophisticated attacks where adversaries can manipulate log data to interfere with security operations and forensic investigations.
The mitigation strategy for this vulnerability involves immediate deployment of patches released by Palo Alto Networks for the affected PAN-OS versions, specifically updating to PAN-OS 8.1.14, 9.0.9, or later versions that contain the necessary authorization controls. Network administrators should also implement additional monitoring of the management server's message handling functions to detect potential unauthorized access attempts. Organizations should review their current logging infrastructure and establish more robust access controls for management server components. This vulnerability aligns with CWE-863 (Authorization Bypass) and can be categorized under ATT&CK technique T1070.001 (Clear Windows Event Logs) and T1070.004 (File Deletion) as it enables unauthorized modification of system log files. The security community should consider this vulnerability as a critical risk for organizations relying on Palo Alto Networks products, particularly those that depend heavily on log integrity for security operations and compliance requirements.