CVE-2006-5990 in VirtualCenter
Summary
by MITRE
VMWare VirtualCenter client 2.x before 2.0.1 Patch 1 (Build 33643) and 1.4.x before 1.4.1 Patch 1 (Build 33425), when server certificate verification is enabled, does not verify the server's X.509 certificate when creating an SSL session, which allows remote malicious servers to spoof valid servers via a man-in-the-middle attack.
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Analysis
by VulDB Data Team • 04/28/2026
The vulnerability described in CVE-2006-5990 represents a critical security flaw in VMware VirtualCenter client versions 2.x before 2.0.1 Patch 1 and 1.4.x before 1.4.1 Patch 1. This issue specifically affects the SSL/TLS certificate verification process within the client application's secure communication framework. The flaw occurs when server certificate verification is enabled, creating a dangerous scenario where the client fails to properly validate the X.509 certificates presented by the server during SSL session establishment. This technical deficiency directly violates fundamental security protocols that should ensure mutual authentication between client and server components in virtualized environments.
The operational impact of this vulnerability is severe and exploitable through man-in-the-middle attack vectors as outlined in the attack pattern framework. When malicious actors compromise a network path between the VMware VirtualCenter client and server, they can present forged SSL certificates that appear legitimate to the vulnerable client. This allows attackers to intercept, modify, or redirect communications without detection, potentially gaining unauthorized access to virtualized infrastructure management functions. The vulnerability essentially undermines the entire SSL/TLS security model that protects sensitive administrative communications, making it particularly dangerous in enterprise environments where VMware VirtualCenter manages critical virtual machine operations and configurations.
From a technical perspective, this vulnerability maps directly to CWE-295 which describes "Improper Certificate Validation" and aligns with ATT&CK technique T1046 for network service scanning and T1566 for credential harvesting through social engineering. The flaw stems from improper implementation of certificate validation routines within the SSL handshake process, where the client application fails to properly verify certificate chains, subject names, and other critical validation parameters. This represents a classic case of insufficient cryptographic validation that allows attackers to bypass authentication mechanisms and establish trust with malicious endpoints. The vulnerability affects not just individual client-server communications but potentially compromises entire virtual infrastructure management systems, as administrators may unknowingly interact with compromised servers while believing they are communicating with legitimate management interfaces.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to the patched versions of VMware VirtualCenter client, implementing additional network-level security controls such as firewall rules that restrict access to management interfaces, and deploying network monitoring solutions to detect anomalous certificate behavior. The patch resolution specifically addresses the certificate verification logic to ensure proper X.509 validation occurs during SSL session establishment. Additionally, administrators should consider implementing certificate pinning mechanisms and maintaining detailed audit logs of SSL connection activities to detect potential exploitation attempts. This vulnerability underscores the critical importance of proper certificate validation in secure communication protocols and serves as a reminder of the potential consequences when cryptographic validation routines are improperly implemented in enterprise management tools.