CVE-2016-7456 in vSphere Data Protection
Summary
by MITRE
VMware vSphere Data Protection (VDP) 5.5.x though 6.1.x has an SSH private key with a publicly known password, which makes it easier for remote attackers to obtain login access via an SSH session.
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Analysis
by VulDB Data Team • 04/24/2025
The vulnerability identified as CVE-2016-7456 affects VMware vSphere Data Protection versions 5.5 through 6.1, representing a critical security flaw that undermines the authentication mechanisms of the platform. This issue stems from the use of a well-known default password for SSH private keys within the VDP environment, creating an easily exploitable weakness that significantly increases the attack surface for remote adversaries. The flaw resides in the default configuration of the virtual appliance, where security defaults are not properly enforced, leaving systems accessible to threat actors who possess basic knowledge of common credential combinations.
This vulnerability falls under the category of weak authentication mechanisms and can be classified as CWE-326 - Inadequate Encryption Strength, with direct implications to CWE-521 - Weak Password Requirements and CWE-798 - Use of Hard-coded Credentials. The technical implementation flaw involves the hardcoded SSH private key that uses a predictable password, making it trivial for attackers to establish unauthorized SSH sessions without requiring additional reconnaissance or exploitation techniques. The vulnerability is particularly concerning because SSH access provides administrative privileges within the vSphere environment, enabling attackers to potentially compromise entire virtual infrastructures.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it creates a persistent backdoor that can be leveraged for lateral movement within virtualized environments. Attackers who successfully exploit this weakness can gain administrative control over the vSphere Data Protection appliance, potentially leading to data exfiltration, system manipulation, and further compromise of connected virtual machines and resources. This vulnerability directly maps to ATT&CK technique T1021.004 - SSH, where adversaries use legitimate remote access tools to establish persistent access. The flaw also enables privilege escalation scenarios and can facilitate more sophisticated attacks such as credential theft, data manipulation, and system disruption that could affect business continuity and compliance requirements.
Organizations should immediately implement mitigation strategies including changing default passwords, disabling unnecessary SSH access, and enforcing strong authentication policies throughout their vSphere environments. System administrators must conduct comprehensive vulnerability assessments to identify all instances of affected vSphere Data Protection appliances and apply the necessary patches or configuration changes. The recommended remediation includes implementing proper key management practices, utilizing certificate-based authentication, and ensuring that all default credentials are changed before system deployment. Additionally, network segmentation and access control policies should be enforced to limit exposure of management interfaces and reduce the attack surface. Regular security audits and vulnerability scanning should be performed to ensure ongoing compliance with security best practices and to identify any potential re-introduction of similar hardcoded credentials within the environment.