CVE-2025-22225 VMware ESXi: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Mar 25, 2025
What to do
- Install VMware's security update for ESXi. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- VMware ESXi Arbitrary Write Vulnerability
- Product
- VMware ESXi
- CISA description
- VMware ESXi contains an arbitrary write vulnerability. Successful exploitation allows an attacker with privileges within the VMX process to trigger an arbitrary kernel write leading to an escape of the sandbox.
- Type of flaw
- Software flaw (CWE-123)
- Confirmed exploited
- Mar 4, 2025 — known to be used in ransomware attacks
- US federal patch deadline
- Mar 25, 2025
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Answering about CVE-2025-22225 ·
Questions about CVE-2025-22225
Is CVE-2025-22225 being exploited?
Yes. CISA added CVE-2025-22225 to its Known Exploited Vulnerabilities catalog on Mar 4, 2025, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2025-22225?
Install VMware's security update for ESXi. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2025-22225?
Only if you use VMware ESXi. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.