CVE-2019-17440 in PAN-OS
Summary
by MITRE
Improper restriction of communications to Log Forwarding Card (LFC) on PA-7000 Series devices with second-generation Switch Management Card (SMC) may allow an attacker with network access to the LFC to gain root access to PAN-OS. This issue affects PAN-OS 9.0 versions prior to 9.0.5-h3 on PA-7080 and PA-7050 devices with an LFC installed and configured. This issue does not affect PA-7000 Series deployments using the first-generation SMC and the Log Processing Card (LPC). This issue does not affect any other PA series devices. This issue does not affect devices without an LFC. This issue does not affect PAN-OS 8.1 or prior releases. This issue only affects a very limited number of customers and we undertook individual outreach to help them upgrade. At the time of publication, all identified customers have upgraded SW or content and are not impacted.
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Analysis
by VulDB Data Team • 03/16/2024
The vulnerability described in CVE-2019-17440 represents a critical privilege escalation flaw affecting specific Palo Alto Networks PA-7000 series firewalls equipped with second-generation Switch Management Cards and Log Forwarding Cards. This issue stems from improper restrictions in the communication protocols between the Log Forwarding Card and the underlying operating system, creating a pathway for unauthorized root access. The vulnerability is particularly concerning because it allows an attacker with network access to the LFC to escalate privileges to the highest system level, effectively compromising the entire device. The flaw is specifically present in PAN-OS 9.0 versions prior to 9.0.5-h3 on PA-7080 and PA-7050 devices, making these particular models and software versions highly susceptible to exploitation.
The technical implementation of this vulnerability involves a failure in access control mechanisms that should normally prevent unauthorized communication between the LFC and the system's core processes. When an attacker gains network access to the LFC interface, they can exploit this weakness to execute commands with root privileges, bypassing normal security boundaries that typically isolate different system components. This represents a classic case of insufficient privilege separation where the communication channel between hardware components lacks proper authentication and authorization checks. The vulnerability manifests due to improper input validation and inadequate sandboxing of communication protocols, allowing malicious payloads to be executed with elevated privileges. According to CWE classification, this vulnerability aligns with CWE-284: Improper Access Control, which encompasses issues where system components fail to properly enforce access restrictions.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over affected devices, potentially enabling them to manipulate network traffic, exfiltrate sensitive data, or establish persistent backdoors within the network infrastructure. Attackers could leverage this vulnerability to gain unauthorized access to the device's configuration, logs, and network monitoring capabilities, effectively compromising the security posture of organizations relying on these specific firewall models. The limited scope of affected devices means that only a small percentage of customers would be impacted, yet the potential for severe consequences remains high due to the root access privileges granted. This vulnerability could enable attackers to perform actions categorized under ATT&CK techniques such as T1059 Command and Scripting Interpreter and T1566 Phishing, as the compromised device could be used for further network infiltration or data exfiltration activities.
Organizations affected by this vulnerability should immediately implement the recommended security patches, specifically upgrading to PAN-OS 9.0.5-h3 or later versions on affected PA-7080 and PA-7050 devices. Network segmentation and access control measures should be enhanced to limit access to LFC interfaces, particularly in environments where physical security cannot be guaranteed. The vulnerability does not affect first-generation SMC deployments or devices without LFC, but organizations should verify their hardware configurations to ensure proper device identification. Additional mitigations include implementing network monitoring to detect anomalous communication patterns on LFC interfaces and conducting regular security assessments to identify any potential exploitation attempts. Organizations should also review their incident response procedures to ensure readiness for potential exploitation of this privilege escalation vulnerability.