CVE-2020-2020 in Cortex XDR Agent
Summary
by MITRE • 12/09/2020
An improper handling of exceptional conditions vulnerability in Cortex XDR Agent allows a local authenticated Windows user to create files in the software's internal program directory that prevents the Cortex XDR Agent from starting. The exceptional condition is persistent and prevents Cortex XDR Agent from starting when the software or machine is restarted. This issue impacts: Cortex XDR Agent 5.0 versions earlier than 5.0.10; Cortex XDR Agent 6.1 versions earlier than 6.1.7; Cortex XDR Agent 7.0 versions earlier than 7.0.3; Cortex XDR Agent 7.1 versions earlier than 7.1.2.
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Analysis
by VulDB Data Team • 12/15/2020
This vulnerability represents a critical improper handling of exceptional conditions flaw within the Cortex XDR Agent software ecosystem, specifically affecting Windows environments where local authenticated users can exploit a design weakness to disrupt agent operations. The vulnerability stems from inadequate error handling mechanisms that fail to properly manage exceptional circumstances during agent execution, creating a persistent condition that fundamentally compromises the software's operational integrity. The flaw allows an authenticated user to manipulate the agent's internal program directory by creating specific files that interfere with normal startup procedures, effectively creating a denial of service condition that persists across system restarts.
The technical implementation of this vulnerability involves the agent's failure to properly validate or sanitize file operations within its internal directory structure during exceptional conditions. When the agent encounters unexpected scenarios during execution, rather than gracefully handling these situations through proper error recovery mechanisms, it creates a state where malicious file creation operations can persistently block agent initialization. This improper exception handling pattern aligns with common software security weaknesses documented in CWE-755, which addresses improper handling of exceptional conditions, and specifically relates to CWE-248, which covers exposure of exception information to an unauthorized actor. The vulnerability exists across multiple major version lines of the Cortex XDR Agent, indicating a fundamental architectural flaw that was not adequately addressed through the software's development lifecycle.
The operational impact of this vulnerability extends beyond simple denial of service, as it creates a persistent state that prevents the security agent from functioning during system restarts, effectively creating a window of vulnerability where endpoint protection is completely absent. This condition directly violates the principle of least privilege and system availability, as a local authenticated user can gain persistent access to compromise the security posture of the entire system. The vulnerability affects critical security infrastructure components and creates a potential attack vector for adversaries seeking to establish persistent presence on compromised systems. According to ATT&CK framework, this vulnerability could be leveraged under technique T1059.001 for command and control operations, or more specifically T1566.001 for initial access through exploitation of software vulnerabilities, potentially enabling further attack progression.
Organizations affected by this vulnerability face significant operational risks as the compromised agent cannot provide continuous monitoring and protection capabilities that are essential for endpoint security. The persistence of this condition across reboots creates a particularly concerning scenario where security teams may not immediately detect the compromise, as the system appears to function normally while the security agent remains disabled. This vulnerability directly impacts the integrity of the security infrastructure and creates potential pathways for more sophisticated attacks that could exploit the agent's absence to perform additional malicious activities. The affected versions span multiple release lines indicating that this was not a transient issue but rather a systemic problem that required comprehensive patching across the software's version hierarchy.
Mitigation strategies should focus on immediate patch deployment to all affected versions of the Cortex XDR Agent, ensuring that the software receives updates that properly address the exceptional condition handling mechanisms. System administrators should also implement monitoring procedures to detect unauthorized file creation in agent directories and establish automated alerts for potential exploitation attempts. The vulnerability highlights the importance of robust error handling and input validation in security software, particularly in agent-based systems where persistence and availability are paramount. Organizations should conduct comprehensive vulnerability assessments to identify any potential exploitation attempts and ensure that their incident response procedures account for this specific type of agent compromise. Additionally, implementing proper access controls and privilege separation can reduce the attack surface available to authenticated local users attempting to exploit this vulnerability.