CVE-2015-1950 in PowerVC Standard Edition
Summary
by MITRE
IBM PowerVC Standard Edition 1.2.2.1 through 1.2.2.2 does not require authentication for access to the Python interpreter with nova credentials, which allows KVM guest OS users to discover certain PowerVC credentials and bypass intended access restrictions via unspecified Python code.
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Analysis
by VulDB Data Team • 04/20/2019
The vulnerability identified as CVE-2015-1950 affects IBM PowerVC Standard Edition versions 1.2.2.1 through 1.2.2.2, representing a critical authentication bypass flaw that compromises the security posture of virtualized environments. This vulnerability resides within the management interface of PowerVC, which serves as a cloud management platform for IBM Power Systems environments. The flaw specifically impacts the Python interpreter component that handles nova credentials, creating an unauthorized access vector that undermines the intended security controls designed to protect sensitive operational information.
The technical implementation of this vulnerability stems from insufficient authentication mechanisms within the PowerVC management interface. When KVM guest operating systems execute unspecified Python code, they can access the Python interpreter without proper authentication requirements. This design flaw allows malicious or authorized users within the guest environment to extract PowerVC credentials that are typically protected by access controls. The vulnerability operates at the application layer and represents a classic case of insufficient authorization checks, which maps directly to CWE-285 - "Improper Authorization" and potentially CWE-306 - "Missing Authentication for Critical Function." The flaw essentially creates a backdoor pathway through which guest operating systems can bypass the normal access control mechanisms that should prevent unauthorized credential exposure.
The operational impact of this vulnerability extends beyond simple credential exposure, as it fundamentally undermines the security isolation between virtual machines and the management infrastructure. Attackers who gain access to KVM guest environments can leverage this vulnerability to obtain nova credentials that provide access to the underlying cloud infrastructure management functions. This creates a significant risk for organizations using PowerVC for cloud management, as the exposure of these credentials could enable attackers to manipulate virtual machine deployments, access sensitive data, or potentially escalate privileges within the cloud environment. The vulnerability particularly affects environments where guest operating systems may be compromised or where insider threats exist, as it allows for credential harvesting without requiring additional attack vectors.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1566 - "Phishing for Information" and T1078 - "Valid Accounts" as it enables adversaries to obtain legitimate credentials through improper access control mechanisms. The attack surface is particularly concerning given that KVM guest environments are often more accessible than the management infrastructure itself, making this a particularly attractive target for attackers seeking to move laterally within cloud environments. Organizations implementing IBM PowerVC should consider this vulnerability as part of their overall security posture assessment, particularly in environments where multiple tenants or untrusted users have access to guest operating systems. The vulnerability also highlights the importance of proper privilege separation and access control implementation in cloud management platforms, as it demonstrates how a single authentication failure can compromise the entire virtualization management infrastructure.
Mitigation strategies should focus on implementing proper authentication mechanisms for all interpreter access points within the PowerVC environment, including immediate patching of affected versions to 1.2.2.3 or later. Organizations should also consider network segmentation to limit access to management interfaces, implement additional monitoring for unauthorized interpreter access attempts, and establish proper credential rotation procedures for nova credentials. The vulnerability underscores the critical importance of regular security assessments and patch management programs, particularly for cloud management platforms that handle sensitive operational credentials and infrastructure control functions.