Palo Alto Networks Security Advisories / CVE-2021-3041

CVE-2021-3041 Cortex XDR Agent: Improper control of user-controlled file leads to local privilege escalation

047910
Severity 7.8 · HIGH
Attack Vector LOCAL
Attack Complexity LOW
Privileges Required LOW
User Interaction NONE
Scope UNCHANGED
Confidentiality Impact HIGH
Integrity Impact HIGH
Availability Impact HIGH

Description

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.

Product Status

VersionsAffectedUnaffected
Cortex XDR Agent 7.2< 7.2.3 or without content update 171 or later>= 7.2.3 with content update 171 or later
Cortex XDR Agent 6.1< 6.1.8>= 6.1.8
Cortex XDR Agent 5.0< 5.0.11>= 5.0.11

Severity: HIGH

CVSSv3.1 Base Score: 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Exploitation Status

Palo Alto Networks is not aware of any malicious exploitation of this issue.

Weakness Type

CWE-427 Uncontrolled Search Path Element

Solution

This issue is fixed in Cortex XDR agent 5.0.11, Cortex XDR agent 6.1.8, Cortex XDR agent 7.2.3, and all later Cortex XDR agent versions.

Content updates are required to resolve this issue and are automatically applied for the agent.

Workarounds and Mitigations

This issue is mitigated by preventing local authenticated Windows users from creating files in the Windows root directory (such as C:\) and ensuring they are unable to manipulate the Windows registry.

Acknowledgments

This issue was found by Robert McCallum of Palo Alto Networks during internal security review.

Timeline

Initial publication
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