CVE-2024-3393
CVE-2024-3393 is a security flaw in Palo Alto Networks PAN-OS, the operating system on Palo Alto Networks’ firewalls. Attackers can crash Palo Alto Networks PAN-OS or stop it working from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 30 Dec 2024.[1]
Palo Alto Networks PAN-OS is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 11.2.3, 11.1.2-h16, 10.2.8-h19 and 10.1.14-h8 of PAN-OS.
Description
CISA calls it a malicious DNS packet in Palo Alto Networks PAN-OS. In its words: “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.”[1]
The underlying weakness is CWE-754, in MITRE’s list of common software weaknesses.[2]
It scores 7.5 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| PAN-OS | 11.2.3 |
| PAN-OS | 11.1.2-h16 |
| PAN-OS | 10.2.8-h19 |
| PAN-OS | 10.1.14-h8 |
Most families won’t have Palo Alto Networks PAN-OS; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 30 Dec 2024, 3 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 20 Jan 2025 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 29%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Palo Alto Networks has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Palo Alto Networks PAN-OS is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 11.2.3, 11.1.2-h16, 10.2.8-h19 and 10.1.14-h8 of PAN-OS), or not in use. CISA gave US government agencies until 20 Jan 2025 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 29%.[4] |
See also
Other Palo Alto Networks PAN-OS flaws
- CVE-2026-0322: code injection ·
- CVE-2026-0257: authentication bypass ·
- CVE-2026-0300: out-of-bounds write ·
- CVE-2025-0111: file read ·
- CVE-2025-0108: authentication bypass ·
- CVE-2024-9474: management interface OS command injection ·
Other Palo Alto Networks flaws
- CVE-2024-9465, Palo Alto Networks Expedition: SQL injection ·
- CVE-2024-9463, Palo Alto Networks Expedition: OS command injection ·
- CVE-2024-5910, Palo Alto Networks Expedition: missing authentication ·
Similar flaws
- CVE-2025-39682, Linux Kernel: improper check for unusual or exceptional conditions ·
- CVE-2023-41993, Apple devices: webKit code execution ·
- CVE-2023-41992, Apple devices: kernel privilege escalation ·
Every Palo Alto Networks flaw on CISA’s list · Everything added in December 2024
References
- ^ Cybersecurity and Infrastructure Security Agency. “Palo Alto Networks PAN-OS Malicious DNS Packet Vulnerability”. Known Exploited Vulnerabilities Catalog, added 30 Dec 2024.
- ^ National Institute of Standards and Technology. “CVE-2024-3393 Detail”. National Vulnerability Database, published 27 Dec 2024.
- ^ Palo Alto Networks. Advisories and fixes: security.paloaltonetworks.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.291, percentile 98.2, 31 Oct 2026.
- CVE Program. “CVE-2024-3393”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.