{"id":59541,"date":"2025-07-21T15:24:05","date_gmt":"2025-07-21T15:24:05","guid":{"rendered":""},"modified":"2025-10-30T05:20:41","modified_gmt":"2025-10-30T11:20:41","slug":"cve-2025-41238-critical-heap-overflow-vulnerability-in-vmware-esxi-workstation-and-fusion","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-41238-critical-heap-overflow-vulnerability-in-vmware-esxi-workstation-and-fusion\/","title":{"rendered":"CVE-2025-41238: Critical Heap-Overflow Vulnerability in VMware ESXi, Workstation, and Fusion<\/strong>"},"content":{"rendered":"

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

In the cybersecurity landscape, a newly discovered vulnerability, identified as CVE-2025-41238, is putting organizations that use VMware ESXi, Workstation, and Fusion at risk. This vulnerability, a heap-overflow issue in the PVSCSI (Paravirtualized SCSI) controller, allows an attacker with local administrative privileges to execute code as the virtual machine’s VMX process running on the host. This type of vulnerability is particularly concerning because of the potential for system<\/a> compromise or data leakage, posing significant threats to enterprise security.<\/p>\n

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

CVE ID: CVE-2025-41238
\nSeverity: Critical (9.3 CVSS Severity Score)
\nAttack Vector: Local
\nPrivileges Required: High (Administrative Privileges)
\nUser Interaction: None
\nImpact: System Compromise and Potential<\/a> Data Leakage<\/p>\n

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

Product | Affected Versions<\/p>\n

VMware ESXi | All versions prior<\/a> to patch
\nVMware Workstation | All versions prior<\/a> to patch
\nVMware Fusion | All versions prior to patch<\/p>\n

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

The vulnerability lies in the PVSCSI controller<\/a>, an important component of VMware software. Specifically, it is a heap-overflow vulnerability that leads to an out-of-bounds write<\/a>. An attacker with local administrative privileges on a virtual machine can exploit this vulnerability to execute code<\/a> as the virtual machine’s VMX process running on the host.
\nOn VMware ESXi, the exploitation is contained within the VMX sandbox and only exploitable with configurations that are unsupported. However, on Workstation and Fusion, this vulnerability may lead<\/a> to code execution on the machine where Workstation or Fusion is installed, hence the high severity score.<\/p>\n

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

While no specific code has been released<\/a> for this exploit, a potential attacker might use a specially crafted payload to trigger the heap-overflow. Conceptually, this might look like:<\/p>\n

$ echo \"malicious payload\" > \/dev\/vmware\/pvscsi\n$ .\/exploit $(cat \/dev\/vmware\/pvscsi)<\/code><\/pre>\n
Note that this is a conceptual example and not real exploit code.<\/p>\n
Mitigation Guidance<\/strong><\/p>\n
The best way to mitigate this vulnerability is to apply vendor patches as soon as they become available. VMware has already released patches for all affected versions of their software, and organizations are strongly advised to apply these updates as quickly as possible.
\nIn the interim, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can provide temporary mitigation. These systems can potentially<\/a> detect and block attempts to exploit this vulnerability.
\nFinally, organizations should reconsider the necessity of allowing local administrative privileges on their virtual machines<\/a>. Restricting such privileges can greatly reduce the attack surface and prevent many types of exploits<\/a>, including this one.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview In the cybersecurity landscape, a newly discovered vulnerability, identified as CVE-2025-41238, is putting organizations that use VMware ESXi, Workstation, and Fusion at risk. This vulnerability, a heap-overflow issue in the PVSCSI (Paravirtualized SCSI) controller, allows an attacker with local administrative privileges to execute code as the virtual machine’s VMX process running on the host. […]<\/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":[86],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-59541","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-vmware","product-vmware-esxi","attack_vector-buffer-overflow"],"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