CVE-2024-3393: Palo Alto Networks PAN-OS Malicious DNS Packet Vulnerability

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run Palo Alto Networks PAN-OS. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2024-12-30, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-01-20; treat that as the outer limit, not the target.
• EPSS 29.1%, percentile 98: FIRST’s model estimates a 29.1% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

A Denial of Service vulnerability in the DNS Security feature of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to send a malicious packet through the data plane of the firewall that reboots the firewall. Repeated attempts to trigger this condition will cause the firewall to enter maintenance mode.

CISA’s summary

Palo Alto Networks PAN-OS contains a vulnerability in parsing and logging malicious DNS packets in the DNS Security feature that, when exploited, allows an unauthenticated attacker to remotely reboot the firewall. Repeated attempts to trigger this condition will cause the firewall to enter maintenance mode.

Weakness type: CWE-754.

Product: Palo Alto Networks PAN-OS · Assigned by: palo_alto · Published: 2024-12-27

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2024-12-30; federal due date 2025-01-20. Known ransomware use: Unknown.
• CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
• CISA SSVC assessment: exploitation active, automatable yes, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 29.12% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

• 2024-12-27 — CVE record published by palo_alto
• 2024-12-30 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2025-01-20 — CISA remediation deadline for US federal agencies
• 2025-10-21 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. security.paloaltonetworks.com security.paloaltonetworks.com

Vulnerability records

1. CVE.org record CVE-2024-3393 cve.org
2. NVD entry CVE-2024-3393 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

All exploited Palo Alto Networks vulnerabilities · Today’s Security Digest