CVE-2020-1993 in PAN-OS
Summary
by MITRE
The GlobalProtect Portal feature in PAN-OS does not set a new session identifier after a successful user login, which allows session fixation attacks, if an attacker is able to control a user's session ID. This issue affects: All PAN-OS 7.1 and 8.0 versions; PAN-OS 8.1 versions earlier than 8.1.14; PAN-OS 9.0 versions earlier than 9.0.8.
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Analysis
by VulDB Data Team • 10/17/2020
The vulnerability identified as CVE-2020-1993 represents a critical session management flaw within the GlobalProtect Portal functionality of Palo Alto Networks PAN-OS software. This issue stems from the improper handling of session identifiers during the authentication process, creating a pathway for sophisticated session fixation attacks that can compromise user authentication and authorization. The vulnerability affects multiple major versions of PAN-OS including 7.1, 8.0, and specific earlier releases of 8.1 and 9.0, making it a widespread concern across the Palo Alto Networks security ecosystem. The root cause lies in the software's failure to generate fresh session identifiers upon successful user authentication, leaving existing session tokens vulnerable to exploitation. This flaw directly violates fundamental web application security principles and aligns with CWE-613, which addresses insufficient session expiration and improper session management. The vulnerability operates under the premise that if an attacker can influence or predict a user's session ID, they can maintain persistent access to the system even after legitimate users have authenticated. This represents a significant threat to network security infrastructure as it undermines the core principle of user authentication and authorization controls.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to establish persistent sessions that can remain undetected for extended periods. When an attacker successfully exploits this vulnerability, they can maintain access to the GlobalProtect Portal even after legitimate users have logged out or their sessions have naturally expired. This creates a persistent threat vector that can be leveraged for data exfiltration, lateral movement within the network, and potential privilege escalation attacks. The vulnerability's exploitation requires minimal prerequisites as attackers only need to be able to control or predict session identifiers, which can be achieved through various means including cross-site scripting attacks or man-in-the-middle positioning. From an attack framework perspective, this vulnerability maps directly to the MITRE ATT&CK technique T1566, which covers credential harvesting through various session management attacks. The affected PAN-OS versions represent a substantial attack surface given the widespread deployment of Palo Alto Networks firewalls and secure access solutions in enterprise environments. Organizations relying on GlobalProtect for remote access and VPN connectivity face significant risk, as this vulnerability can be exploited to gain unauthorized access to protected network resources.
Mitigation strategies for CVE-2020-1993 require immediate implementation of both software updates and operational controls to address the session fixation vulnerability. The primary remediation involves upgrading affected PAN-OS versions to the patched releases, specifically PAN-OS 8.1.14 or later for 8.1 versions, and PAN-OS 9.0.8 or later for 9.0 versions. This upgrade process should be prioritized at the highest security level due to the vulnerability's potential for persistent unauthorized access. Network administrators should also implement additional controls such as session timeout configurations, regular session token rotation, and monitoring for unusual authentication patterns. The vulnerability's impact is compounded by the fact that it affects multiple major releases, requiring comprehensive patch management across all affected systems. Organizations should conduct thorough vulnerability assessments to identify any systems running vulnerable versions of PAN-OS and implement network segmentation to limit the potential impact of successful exploitation. Security monitoring should be enhanced to detect anomalous session behavior, including multiple simultaneous connections from the same session ID or unusual authentication patterns. Additionally, implementing proper input validation and secure session management practices in network infrastructure components can help prevent similar vulnerabilities from manifesting in other security solutions. The vulnerability's classification under CWE-613 emphasizes the need for robust session management protocols that ensure proper session identifier regeneration upon authentication events. Organizations should also consider implementing multi-factor authentication mechanisms as additional protection layers, as session fixation attacks can be particularly dangerous when combined with other authentication bypass techniques.