CVE-2021-3031 PAN-OS: Information exposure in Ethernet data frame construction (Etherleak)
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
| Versions | Affected | Unaffected |
|---|---|---|
| PAN-OS 10.0 | None | 10.0.* |
| 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 8.0 | 8.0.* on PA-200, PA-220, PA-500, PA-5000 Series, PA-800, PA-3000 Series, PA-3200 Series, PA-5200 Series, PA-7000 Series | None |
| PAN-OS 7.1 | 7.1.* 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 | None |
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
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.