Palo Alto Networks Security Advisories / CVE-2021-3042

CVE-2021-3042 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 (PE) 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.

Exploiting this vulnerability requires the user to have file creation privilege in the Windows root directory (such as C:\).

This issue impacts:

All versions of Cortex XDR agent 6.1 without content update 181 or a later version;

All versions of Cortex XDR agent 7.2 without content update 181 or a later version;

All versions of Cortex XDR agent 7.3 without content update 181 or a later version.

Cortex XDR agent 5.0 versions are not impacted by this issue.

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

Product Status

VersionsAffectedUnaffected
Cortex XDR Agent 7.37.3.* without content update 181 or later on Windows7.3.* with content update 181 or later on Windows
Cortex XDR Agent 7.27.2.* without content update 181 or later on Windows 7.2.* with content update 181 or later on Windows
Cortex XDR Agent 6.16.1.* without content update 181 or later on Windows 6.1.* with content update 181 or later on Windows
Cortex XDR Agent 5.0Noneall

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 6.1, Cortex XDR agent 7.2, Cortex XDR agent 7.3, and all later Cortex XDR agent versions with content update 181 or later content updates.

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:\).

Acknowledgments

Palo Alto Networks thanks Xavier DANEST of Decathlon for discovering and reporting this issue.

Timeline

Initial publication
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