CVE-2017-4923 in vCenter Server
Summary
by MITRE
VMware vCenter Server (6.5 prior to 6.5 U1) contains an information disclosure vulnerability. This issue may allow plaintext credentials to be obtained when using the vCenter Server Appliance file-based backup feature.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/06/2021
The vulnerability identified as CVE-2017-4923 represents a critical information disclosure flaw within VMware vCenter Server versions prior to 6.5 Update 1. This vulnerability specifically affects the vCenter Server Appliance file-based backup feature, creating a significant security risk for organizations relying on VMware's virtualization infrastructure. The flaw enables unauthorized access to plaintext credentials that are stored within backup files, potentially compromising the entire virtualized environment. This issue falls under the broader category of information disclosure vulnerabilities, which are classified as CWE-200 in the Common Weakness Enumeration framework, indicating a failure to properly protect sensitive data from unauthorized access.
The technical implementation of this vulnerability stems from improper handling of credentials within the backup process of vCenter Server appliances. When administrators perform file-based backups using the vCenter Server Appliance, the system stores authentication credentials in plaintext format within the backup archives. This design flaw allows attackers who gain access to backup files to directly extract username and password combinations without requiring additional exploitation techniques. The vulnerability is particularly concerning because it affects the backup functionality itself, which is typically considered a trusted administrative operation within the virtualization environment. Attackers can leverage this weakness through various attack vectors including direct file system access, network-based attacks, or by compromising systems that have access to backup storage locations. The attack pattern aligns with techniques described in the MITRE ATT&CK framework under the T1005 category for data from local system, where adversaries collect information from local systems through backup files.
The operational impact of CVE-2017-4923 extends beyond simple credential exposure, as it can lead to complete compromise of the virtualized infrastructure. Once attackers obtain plaintext credentials through this vulnerability, they can establish persistent access to vCenter Server, potentially gaining control over all virtual machines managed by that server. The exposure of administrative credentials enables attackers to perform privileged operations including creating new virtual machines, modifying existing configurations, accessing sensitive data stored within virtual environments, and potentially escalating privileges to other systems within the network. Organizations using vulnerable versions of vCenter Server face significant risk of unauthorized access to their entire virtual infrastructure, making this vulnerability particularly dangerous in enterprise environments where vCenter servers manage critical workloads. The impact is amplified because vCenter Server serves as the central management point for VMware environments, making it a prime target for attackers seeking long-term access to network resources.
Mitigation strategies for CVE-2017-4923 primarily focus on immediate remediation through software updates and operational best practices. Organizations should immediately upgrade to VMware vCenter Server 6.5 Update 1 or later versions to address the vulnerability at its source. VMware released patches specifically designed to resolve the credential handling issue in backup files, eliminating the plaintext exposure risk. Additionally, administrators should implement strict access controls for backup storage locations, ensuring that only authorized personnel have access to backup files containing sensitive information. The implementation of encryption for backup files, proper file system permissions, and regular monitoring of backup access logs can provide additional layers of protection. Organizations should also consider implementing network segmentation to limit access to vCenter Server environments and establish robust backup management policies that include regular credential rotation and secure backup file handling procedures. These measures align with security best practices outlined in industry standards and help prevent similar vulnerabilities from being exploited in the future.