Palo Alto Networks Security Advisories / CVE-2021-3031

CVE-2021-3031 PAN-OS: Information exposure in Ethernet data frame construction (Etherleak)

047910
Severity 4.3 · MEDIUM
Attack Vector ADJACENT_NETWORK
Attack Complexity LOW
Privileges Required NONE
User Interaction NONE
Scope UNCHANGED
Confidentiality Impact LOW
Integrity Impact NONE
Availability Impact NONE

Description

Padding bytes in Ethernet packets on PA-200, PA-220, PA-500, PA-5000 Series, PA-800, PA-2000 Series, PA-3000 Series, PA-3200 Series, PA-5200 Series, and PA-7000 Series firewalls are not cleared before the data frame is created. This leaks a small amount of random information from the firewall memory into the Ethernet packets. An attacker on the same Ethernet subnet as the PAN-OS firewall is able to collect potentially sensitive information from these packets.

This issue is also known as Etherleak and is detected by security scanners as CVE-2003-0001.

This issue impacts:

PAN-OS 8.1 version earlier than PAN-OS 8.1.18;

PAN-OS 9.0 versions earlier than PAN-OS 9.0.12;

PAN-OS 9.1 versions earlier than PAN-OS 9.1.5;

All versions of PAN-OS 8.0 and PAN-OS 7.1.

Product Status

VersionsAffectedUnaffected
PAN-OS 10.0None10.0.*
PAN-OS 9.1< 9.1.5 on PA-220, PA-800, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series>= 9.1.5
PAN-OS 9.0< 9.0.12 on PA-220, PA-800, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series>= 9.0.12
PAN-OS 8.1< 8.1.18 on PA-200, PA-220, PA-500, PA-5000 Series, PA-800, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series>= 8.1.18
PAN-OS 8.08.0.* on PA-200, PA-220, PA-500, PA-5000 Series, PA-800, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series
PAN-OS 7.17.1.* on PA-200, PA-220, PA-500, PA-5000 Series, PA-800, PA-2000 Series, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series

Severity: MEDIUM

CVSSv3.1 Base Score: 4.3 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Exploitation Status

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

Weakness Type

CWE-200 Information Exposure

Solution

This issue is fixed in PAN-OS 8.1.18, PAN-OS 9.0.12, PAN-OS 9.1.5, and all later PAN-OS versions.

Workarounds and Mitigations

There is no workaround to prevent the information leak in the Ethernet packets; however, restricting access to the networks mitigates the risk of this issue.

Acknowledgments

This issue was found by a customer of Palo Alto Networks during a security review.

Timeline

Update affected hardware series names for compatible PAN-OS versions.
Update affected hardware series names for compatible PAN-OS versions.
Initial publication
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