How severe is CVE-2021-3047?

CVE-2021-3047 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-3047 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3047?

CVE-2021-3047 affects Paloaltonetworks Pan-os. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3047?

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

When was CVE-2021-3047 published?

CVE-2021-3047 was published on 2021-08-11 and last updated on 2026-06-17.

CVE-2021-3047

CVE-2021-3047 is a medium-severity vulnerability in Paloaltonetworks Pan-os with a CVSS 3.x base score of 4.2. 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-338.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
CVSS v2: 3.5
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-338
Affected product: Paloaltonetworks Pan-os
Published: 2021-08-11
Last modified: 2026-06-17

Description

A cryptographically weak pseudo-random number generator (PRNG) is used during authentication to the Palo Alto Networks PAN-OS web interface. This enables an authenticated attacker, with the capability to observe their own authentication secrets over a long duration on the PAN-OS appliance, to impersonate another authenticated web interface administrator's session. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.19; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14; PAN-OS 9.1 versions earlier than PAN-OS 9.1.10; PAN-OS 10.0 versions earlier than PAN-OS 10.0.4. PAN-OS 10.1 versions are not impacted.

Frequently asked questions

What is CVE-2021-3047?: A cryptographically weak pseudo-random number generator (PRNG) is used during authentication to the Palo Alto Networks PAN-OS web interface. This enables an authenticated attacker, with the capability to observe their own authentication secrets over a long duration on the PAN-OS appliance, to impersonate another authenticated web interface administrator's session. This issue impacts: PAN-OS 8.1 versions earlier than PAN-OS 8.1.19; PAN-OS 9.0 versions earlier than PAN-OS 9.0.14; PAN-OS 9.1 versions earlier than PAN-OS 9.1.10; PAN-OS 10.0 versions earlier than PAN-OS 10.0.4. PAN-OS 10.1 versions are not impacted.
How severe is CVE-2021-3047?: CVE-2021-3047 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-3047 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3047?: CVE-2021-3047 affects Paloaltonetworks Pan-os. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3047?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3047 published?: CVE-2021-3047 was published on 2021-08-11 and last updated on 2026-06-17.

References

https://security.paloaltonetworks.com/CVE-2021-3047

Affected products (1)

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

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