CVE-2016-9149 in PAN-OS
Summary
by MITRE
The Addresses Object parser in Palo Alto Networks PAN-OS before 5.0.20, 5.1.x before 5.1.13, 6.0.x before 6.0.15, 6.1.x before 6.1.15, 7.0.x before 7.0.11, and 7.1.x before 7.1.6 mishandles single quote characters, which allows remote authenticated users to conduct XPath injection attacks via a crafted string.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/04/2022
The vulnerability identified as CVE-2016-9149 represents a critical XPath injection flaw within the Addresses Object parser of Palo Alto Networks PAN-OS software across multiple versions. This vulnerability specifically manifests when the system processes user input containing single quote characters within address objects, creating an exploitable condition that enables authenticated attackers to manipulate XPath queries. The flaw exists in the input validation and sanitization mechanisms that handle address object definitions, which are fundamental components used for network security policy enforcement and address management within the firewall infrastructure.
The technical implementation of this vulnerability stems from inadequate handling of special characters during the parsing of address objects within the PAN-OS configuration management system. When a single quote character is introduced into an address object definition, the system fails to properly escape or sanitize this input before incorporating it into XPath queries that are subsequently executed against the internal configuration database. This improper input handling creates an XPath injection vector where attackers can craft malicious strings that alter the intended query behavior, potentially allowing them to extract sensitive configuration data, bypass access controls, or manipulate address object definitions. The vulnerability is classified under CWE-643 as improper neutralization of data within XPath queries, which directly maps to the insecure programming practices in the PAN-OS address object parser implementation.
The operational impact of this vulnerability extends beyond simple data manipulation, as it provides authenticated attackers with significant privileges to compromise network security policies. An attacker who has already gained authentication credentials to the PAN-OS management interface can exploit this vulnerability to perform unauthorized actions within the firewall's configuration space. The attack surface includes potential access to sensitive network information, modification of address objects that could affect security policy enforcement, and possible privilege escalation within the system. This vulnerability particularly affects organizations relying on Palo Alto Networks firewalls for network security, as it could allow attackers to manipulate address-based security rules, potentially enabling them to bypass network segmentation controls or access restricted network segments.
Organizations should implement immediate mitigations including applying the vendor-provided security updates and patches that address this XPath injection vulnerability in PAN-OS versions prior to the specified fixed releases. The recommended remediation strategy involves upgrading to PAN-OS versions 5.0.20, 5.1.13, 6.0.15, 6.1.15, 7.0.11, and 7.1.6 respectively, which contain proper input sanitization mechanisms for handling special characters in address object definitions. Additionally, network administrators should consider implementing additional monitoring and logging controls to detect anomalous configuration changes that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.008 for input validation and T1566.001 for credential access, making it particularly concerning for organizations following MITRE ATT&CK framework for threat modeling and security controls implementation.