CVE-2021-3041 in Cortex XDR Agent
Summary
by MITRE • 06/10/2021
A local privilege escalation vulnerability exists in the Palo Alto Networks Cortex XDR agent on Windows platforms that enables an authenticated local Windows user to execute programs with SYSTEM privileges. This requires the user to have the privilege to create files in the Windows root directory or to manipulate key registry values. This issue impacts: Cortex XDR agent 5.0 versions earlier than Cortex XDR agent 5.0.11; Cortex XDR agent 6.1 versions earlier than Cortex XDR agent 6.1.8; Cortex XDR agent 7.2 versions earlier than Cortex XDR agent 7.2.3; All versions of Cortex XDR agent 7.2 without content update release 171 or a later version.
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Analysis
by VulDB Data Team • 06/13/2021
The vulnerability described in CVE-2021-3041 represents a critical local privilege escalation flaw within Palo Alto Networks Cortex XDR agent implementations on Windows operating systems. This security weakness allows authenticated local users to elevate their privileges to the SYSTEM level, effectively granting them complete control over the affected system. The vulnerability specifically targets the agent's handling of file creation and registry manipulation operations within the Windows root directory, creating a pathway for malicious actors to execute arbitrary code with the highest available privileges. The flaw demonstrates a fundamental failure in privilege management and access control mechanisms within the agent's operational framework, potentially compromising the entire system's security posture.
Technical exploitation of this vulnerability requires an authenticated user to possess either the ability to create files in the Windows root directory or to manipulate critical registry values that the agent manages. The underlying flaw stems from improper privilege validation and inadequate sandboxing of agent operations, allowing local users to manipulate the agent's execution environment through file system or registry modifications. This type of vulnerability falls under the CWE-269: "Improper Privilege Management" category, which specifically addresses weaknesses in how software handles privilege levels and access controls. The vulnerability's exploitation pathway demonstrates a classic privilege escalation vector where insufficient input validation and privilege boundary enforcement create opportunities for unauthorized elevation of privileges.
The operational impact of CVE-2021-3041 extends beyond simple privilege escalation, as it provides attackers with SYSTEM-level access that enables them to bypass all standard security controls and monitoring mechanisms. Once elevated to SYSTEM privileges, malicious actors can modify system files, install rootkits, disable security features, and access all data on the system regardless of user permissions. This vulnerability directly affects multiple versions of the Cortex XDR agent, with specific affected releases including 5.0.x before 5.0.11, 6.1.x before 6.1.8, 7.2.x before 7.2.3, and all 7.2.x versions without content update release 171 or later. The widespread impact across these version ranges indicates a systemic issue in the agent's privilege handling architecture that required immediate patching across multiple product lines.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of the relevant security patches provided by Palo Alto Networks. The mitigation strategy should include verifying that all affected Cortex XDR agent versions have been updated to their patched releases, with particular attention to the content update requirements for version 7.2. System administrators should also implement additional monitoring for unusual file creation patterns in the Windows root directory and registry modifications that could indicate exploitation attempts. From a threat hunting perspective, this vulnerability maps to ATT&CK technique T1068: "Local Privilege Escalation" and T1547: "Registry Run Keys / Startup Folder," as attackers may attempt to establish persistence through these methods. The vulnerability's presence in the Cortex XDR agent also raises concerns about the agent's design philosophy and its potential to become a persistent attack vector, as the agent typically runs with elevated privileges to perform security operations. Security teams should conduct comprehensive vulnerability assessments to identify any potential exploitation attempts and ensure that all systems have been properly patched to prevent unauthorized privilege escalation through this specific vulnerability.