{"id":59539,"date":"2025-07-21T13:22:33","date_gmt":"2025-07-21T13:22:33","guid":{"rendered":""},"modified":"2025-09-28T06:48:24","modified_gmt":"2025-09-28T12:48:24","slug":"cve-2025-41236-critical-integer-overflow-vulnerability-in-vmware-s-vmxnet3-virtual-network-adapter","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-41236-critical-integer-overflow-vulnerability-in-vmware-s-vmxnet3-virtual-network-adapter\/","title":{"rendered":"CVE-2025-41236: Critical Integer-Overflow Vulnerability in VMware’s VMXNET3 Virtual Network Adapter<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

An alarming vulnerability, CVE-2025-41236, has been discovered in VMware’s ESXi, Workstation, and Fusion products. This vulnerability exists within the VMXNET3 virtual network adapter and poses a significant threat to virtual machines running these VMware products. The vulnerability is of particular concern because it allows<\/a> a malicious actor with local administrative privileges to potentially execute code on the host system. Understanding and mitigating this issue is crucial for maintaining the security and integrity<\/a> of virtual environments.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

–
\nCVE ID<\/strong>
\n: CVE-2025-41236
\n–
\nSeverity<\/strong>
\n: Critical (9.3 CVSS Severity Score)
\n–
\nAttack Vector<\/strong>
\n: Local
\n–
\nPrivileges Required<\/strong>
\n: High (Local Administrative Privileges<\/a>)
\n–
\nUser Interaction<\/strong>
\n: None
\n–
\nImpact<\/strong>
\n: Potential system<\/a> compromise and data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

VMware ESXi<\/a> | All versions with VMXNET3
\nVMware Workstation | All versions with VMXNET3
\nVMware Fusion | All versions with VMXNET3<\/p>\n

How the Exploit Works<\/strong><\/p>\n

This exploit utilizes an integer-overflow vulnerability in the VMXNET3 virtual network<\/a> adapter. An attacker with local administrative privileges on the virtual machine can manipulate specific parameters or data inputs<\/a> to trigger an overflow condition. This overflow can cause the system to behave unpredictably, potentially allowing code execution<\/a> on the host.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Given that this vulnerability requires local<\/a> access, an attacker might use a shell command similar to the following to exploit the condition:<\/p>\n

$ echo -ne \"\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\" > \/dev\/vmxnet3\n$ echo -ne \"\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\" > \/dev\/vmxnet3<\/code><\/pre>\n
This simplified example is just to illustrate the concept of an integer overflow<\/a>. The actual exploit would likely involve more complex manipulation of the network adapter’s parameters.<\/p>\n
Mitigation and Remediation<\/strong><\/p>\n
The most effective solution to address this vulnerability<\/a> is to apply the vendor-supplied patch. VMware has released patches that fix this issue in the affected<\/a> products. If it is not immediately possible to apply these patches, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. However, these should not be considered long-term solutions, as they don’t address the root cause of the vulnerability<\/a>.
\nPlease ensure to follow your organization’s patch management policy and apply the patches immediately to mitigate the risk associated with CVE-2025-41236.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview An alarming vulnerability, CVE-2025-41236, has been discovered in VMware’s ESXi, Workstation, and Fusion products. This vulnerability exists within the VMXNET3 virtual network adapter and poses a significant threat to virtual machines running these VMware products. The vulnerability is of particular concern because it allows a malicious actor with local administrative privileges to potentially execute […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[93],"product":[107],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-59539","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-vmware","product-vmware-esxi"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t