CVE-2020-17352 in XG Firewall
Summary
by MITRE
Two OS command injection vulnerabilities in the User Portal of Sophos XG Firewall through 2020-08-05 potentially allow an authenticated attacker to remotely execute arbitrary code.
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Analysis
by VulDB Data Team • 08/08/2020
The vulnerability CVE-2020-17352 represents a critical security flaw in Sophos XG Firewall's User Portal component that enables authenticated attackers to perform remote code execution through OS command injection attacks. This vulnerability specifically affects versions of the Sophos XG Firewall released through August 5, 2020, making it a significant concern for organizations relying on this network security solution. The flaw resides in the User Portal functionality which handles user authentication and access management, creating a potential entry point for malicious actors who have already gained initial access credentials. The vulnerability's impact extends beyond simple privilege escalation as it allows full system compromise through arbitrary command execution, potentially enabling attackers to gain complete control over the firewall's operating system and underlying infrastructure.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the User Portal's command processing mechanisms. Attackers can exploit this weakness by injecting malicious commands through specifically crafted parameters or input fields that are subsequently executed by the underlying operating system. This type of vulnerability aligns with CWE-77 and CWE-88 classifications, which specifically address command injection flaws where user-supplied data is improperly incorporated into system commands without proper sanitization. The attack vector requires an authenticated session, meaning that an attacker must first obtain valid user credentials, but once achieved, the privilege level of the authenticated user determines the scope of potential system compromise. The vulnerability's exploitation typically involves crafting malicious payloads that bypass existing security controls and execute commands with the privileges of the web application process, often running with elevated system permissions.
The operational impact of CVE-2020-17352 is severe and multifaceted, potentially allowing attackers to establish persistent access, exfiltrate sensitive data, modify firewall configurations, and disrupt network security operations. Organizations may experience complete loss of network security control as attackers can modify firewall rules, disable security features, or redirect traffic through malicious command execution. The vulnerability's presence in the User Portal component creates a particularly dangerous scenario since this interface often requires administrative privileges for legitimate operations, making the potential damage scale with the user's permission level. Network defenders face significant challenges in detecting exploitation attempts as the injected commands may appear as legitimate system operations, potentially evading traditional security monitoring solutions and intrusion detection systems. This vulnerability also poses risks to network availability and integrity, as attackers could potentially cause denial of service conditions or manipulate network traffic routing through command injection attacks.
Organizations should immediately implement mitigations including applying the latest security patches released by Sophos to address the identified command injection vulnerabilities. Network segmentation and privilege separation should be enforced to limit the potential impact of credential compromise, ensuring that even if an attacker gains access to the User Portal, they cannot escalate privileges to full system control. Security monitoring should be enhanced to detect anomalous command execution patterns and unusual authentication activities within the User Portal interface. Regular security assessments and penetration testing should be conducted to identify additional vulnerabilities in similar components and ensure comprehensive protection against command injection attacks. The vulnerability highlights the importance of implementing defense-in-depth strategies and adhering to secure coding practices that prevent user input from being directly incorporated into system commands without proper validation and sanitization. Organizations should also consider implementing web application firewalls and additional access controls to provide layered protection against similar exploitation techniques. The incident underscores the critical need for regular security updates and vulnerability management programs to prevent exploitation of known vulnerabilities in network infrastructure components.