VMware ESXi Arbitrary Write
CVE-2025-22225 is a high-severity out-of-bounds write vulnerability in VMware ESXi, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, without any action from a user. The record lists versions ESXi80U3d-24585383, ESXi80U2d-24585300, ESXi70U3s-24585291 as the first without the flaw, so updating VMware ESXi to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on March 4, 2025, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update VMware ESXi to ESXi80U3d-24585383 or ESXi80U2d-24585300 or ESXi70U3s-24585291, whichever matches your release line, or a later version.
- CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Read the advisory on support.broadcom.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| VMware ESXi | VMware ESXi | 8.0 up to, but not including, ESXi80U3d-24585383; 8.0 up to, but not including, ESXi80U2d-24585300; 7.0 up to, but not including, ESXi70U3s-24585291 | ESXi80U3d-24585383, ESXi80U2d-24585300, ESXi70U3s-24585291 |
| VMware Cloud Foundation | VMware Cloud Foundation | 5.x, 4.5.x | Not stated |
| VMware Telco Cloud Platform | VMware Telco Cloud Platform | 5.x, 4.x, 3.x, 2.x | Not stated |
| VMware Telco Cloud Infrastructure | VMware Telco Cloud Infrastructure | 3.x, 2.x | Not stated |
| VMware | Esxi | 7.0; 8.0 | Not stated |
| VMware | Cloud Foundation | Not specified in the record | Not stated |
| VMware | Telco Cloud Infrastructure | 2.2; 2.5; 2.7; 3.0 | Not stated |
| VMware | Telco Cloud Platform | 2.0; 2.5; 2.7; 3.0; 4.0; 4.0.1; 5.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.2 | High | CNA (vmware.com) |
| CVSS 3.1 | 8.2 | High | NVD |
Official description
VMware ESXi contains an arbitrary write vulnerability. A malicious actor with privileges within the VMX process may trigger an arbitrary kernel write leading to an escape of the sandbox.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-22225US Government Resource
Other vulnerabilities in VMware ESXi
- 7.2 High severity
VMware ESXi Authentication Bypass Exploited
- 7.8 High severity
- 7.1 High severity
- 8.2 High severity
- 9.8 Critical severity
VMware ESXi OpenSLP Use-After-Free Exploited
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
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