CVE-2017-8390 in PAN-OS
Summary
by MITRE
The DNS Proxy in Palo Alto Networks PAN-OS before 6.1.18, 7.x before 7.0.16, 7.1.x before 7.1.11, and 8.x before 8.0.3 allows remote attackers to execute arbitrary code via a crafted domain name.
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Analysis
by VulDB Data Team • 10/31/2019
The vulnerability identified as CVE-2017-8390 represents a critical remote code execution flaw within the DNS Proxy functionality of Palo Alto Networks PAN-OS operating systems. This vulnerability affects multiple version branches including 6.1.x before 6.1.18, 7.x before 7.0.16, 7.1.x before 7.1.11, and 8.x before 8.0.3, creating a widespread impact across the network security platform's deployment landscape. The flaw resides in how the system processes and handles domain name requests through its DNS proxy service, which serves as a critical component for network traffic filtering and security policy enforcement.
The technical implementation of this vulnerability stems from improper input validation and handling within the DNS proxy module. When processing crafted domain names, the system fails to adequately sanitize or validate the incoming data, allowing maliciously constructed domain names to trigger unexpected behavior within the application's memory management and execution pathways. This improper handling creates opportunities for attackers to inject and execute arbitrary code with the privileges of the affected service process. The vulnerability manifests through a buffer overflow condition or similar memory corruption mechanism that enables attackers to manipulate the execution flow of the DNS proxy service, potentially leading to complete system compromise.
From an operational perspective, this vulnerability presents severe implications for organizations relying on Palo Alto Networks firewalls for network security. The remote exploitation capability means attackers can compromise affected systems without requiring physical access or local network presence, making it particularly dangerous for enterprise environments where firewalls serve as primary security perimeters. The DNS proxy functionality is typically enabled by default in many configurations, increasing the attack surface exposure. Successful exploitation could result in full system compromise, allowing attackers to establish persistence, exfiltrate sensitive data, or use the compromised device as a pivot point for further network infiltration attacks. The vulnerability's impact extends beyond immediate system compromise to potentially affect the entire network security infrastructure that relies on proper DNS proxy functionality.
Organizations should implement immediate mitigations including applying the vendor-provided security updates and patches for PAN-OS versions affected by CVE-2017-8390. The affected versions should be upgraded to the patched releases mentioned in the vendor advisories, specifically 6.1.18, 7.0.16, 7.1.11, and 8.0.3 respectively. Network administrators should also consider implementing additional monitoring and detection measures to identify potential exploitation attempts, including anomaly detection for unusual DNS query patterns and traffic flows that might indicate exploitation activity. Security teams should review their current firewall configurations to ensure that unnecessary DNS proxy functionality is disabled where possible, reducing the attack surface. The vulnerability aligns with CWE-121 for heap-based buffer overflow conditions and maps to ATT&CK technique T1059 for command and scripting interpreter, highlighting the potential for attackers to leverage this vulnerability for execution-based attacks within their target environments.