How severe is CVE-2021-3031?

CVE-2021-3031 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-3031 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3031?

CVE-2021-3031 affects Paloaltonetworks Pan-os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3031?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3031 published?

CVE-2021-3031 was published on 2021-01-13 and last updated on 2026-06-17.

CVE-2021-3031

CVE-2021-3031 is a medium-severity vulnerability in Paloaltonetworks Pan-os with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-212.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 3.3
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-212
Affected product: Paloaltonetworks Pan-os
Published: 2021-01-13
Last modified: 2026-06-17

Description

Padding bytes in Ethernet packets on PA-200, PA-220, PA-500, 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.

Frequently asked questions

What is CVE-2021-3031?: Padding bytes in Ethernet packets on PA-200, PA-220, PA-500, 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.
How severe is CVE-2021-3031?: CVE-2021-3031 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-3031 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3031?: CVE-2021-3031 affects Paloaltonetworks Pan-os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3031?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3031 published?: CVE-2021-3031 was published on 2021-01-13 and last updated on 2026-06-17.

References

https://security.paloaltonetworks.com/CVE-2021-3031

Affected products (1)

cpe:2.3:o:paloaltonetworks:pan-os:*:*:*:*:*:*:*:*

More vulnerabilities in Paloaltonetworks Pan-os

CVE-2024-3400 — Critical (CVSS 10.0): A command injection as a result of arbitrary file creation vulnerability in the GlobalProtect feature of Palo Alto…
CVE-2020-2021 — Critical (CVSS 10.0): When Security Assertion Markup Language (SAML) authentication is enabled and the 'Validate Identity Provider…
CVE-2019-17440 — Critical (CVSS 10.0): Improper restriction of communications to Log Forwarding Card (LFC) on PA-7000 Series devices with second-generation…
CVE-2012-6603 — Critical (CVSS 10.0): The web management UI in Palo Alto Networks PAN-OS before 3.1.12, 4.0.x before 4.0.10, and 4.1.x before 4.1.4 allows…
CVE-2012-6601 — Critical (CVSS 10.0): The device-management command-line interface in Palo Alto Networks PAN-OS before 3.1.12, 4.0.x before 4.0.10, and 4.1.x…
CVE-2012-6593 — Critical (CVSS 10.0): Palo Alto Networks PAN-OS before 3.1.10 and 4.0.x before 4.0.4 allows remote attackers to execute arbitrary commands…

All CVEs affecting Paloaltonetworks Pan-os →

Other CWE-212 vulnerabilities

CVE-2022-2818 — Critical (CVSS 9.8): Improper Removal of Sensitive Information Before Storage or Transfer in GitHub repository cockpit-hq/cockpit prior to…
CVE-2020-11684 — Critical (CVSS 9.1): AT91bootstrap before 3.9.2 does not properly wipe encryption and authentication keys from memory before passing control…
CVE-2026-39937 — High (CVSS 8.8): Improper removal of sensitive information before storage or transfer vulnerability in The Wikimedia Foundation…
CVE-2022-30617 — High (CVSS 8.8): An authenticated user with access to the Strapi admin panel can view private and sensitive data, such as email and…
CVE-2022-0355 — High (CVSS 8.8): Improper Removal of Sensitive Information Before Storage or Transfer in NPM simple-get prior to 4.0.1.
CVE-2021-0340 — High (CVSS 8.8): In parseNextBox of IsoInterface.java, there is a possible leak of unredacted location information due to improper input…

Browse all CWE-212 vulnerabilities →