Overview
In today’s digital landscape, cybersecurity has become a top priority for businesses and organizations. A single vulnerability can open the door to catastrophic data breaches and system compromises. This blog post delves into one such vulnerability, CVE-2025-41251, a critical weakness found within VMware NSX’s password recovery mechanism. This vulnerability threatens numerous versions of VMware NSX and VMware Cloud Foundation, and if unaddressed, could lead to potential system compromise or data leakage. With a CVSS Severity Score of 8.1, this vulnerability is one that cannot be overlooked.
Vulnerability Summary
CVE ID: CVE-2025-41251
Severity: Important, CVSSv3: 8.1 (High)
Attack Vector: Remote, unauthenticated
Privileges Required: None
User Interaction: None
Impact: Username enumeration leading to credential brute force risk, potential system compromise or data leakage.
Affected Products
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Product | Affected Versions
VMware NSX | 9.x.x.x, 4.2.x, 4.1.x, 4.0.x
NSX-T | 3.x
VMware Cloud Foundation (with NSX) | 5.x, 4.5.x
How the Exploit Works
The vulnerability lies within the password recovery mechanism of VMware’s NSX product. An unauthenticated attacker could exploit this vulnerability to enumerate valid usernames potentially. This enumeration process could then help facilitate a brute-force attack by trying combinations of usernames and passwords until the correct one is found. Given that the attack can be carried out remotely, it significantly increases the risk associated with this vulnerability.
Conceptual Example Code
A conceptual example of how the vulnerability might be exploited could be a crafted HTTP request to the password recovery endpoint. An example would look like this:
GET /password_recovery HTTP/1.1
Host: target.example.com
{ "username": "admin" }This request would return a response that could inadvertently reveal whether the username “admin” is valid or not, thereby enabling username enumeration.
Impact Summary
If successfully exploited, CVE-2025-41251 could lead to a severe security breach. The malicious actor could potentially gain unauthorized access to the system, leading to system compromise or data leakage.
Mitigation Guidance
Given the severity of the vulnerability, users are advised to apply the vendor patch immediately. VMware has released fixed versions for the affected products: NSX 9.0.1.0, 4.2.2.2/4.2.3.1, 4.1.2.7; NSX-T 3.2.4.3; and a CCF async patch (KB88287). In scenarios where immediate patching is not possible, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) could serve as temporary mitigation. However, these should not be considered long-term solutions as they do not address the root cause of the vulnerability.
Acknowledgments
This vulnerability was reported by the National Security Agency, highlighting the importance of collaborative efforts in enhancing cybersecurity across the board.
