CVE-2018-15795 in CredHub Service Broker
Summary
by MITRE
Pivotal CredHub Service Broker, versions prior to 1.1.0, uses a guessable form of random number generation in creating service broker's UAA client. A remote malicious user may guess the client secret and obtain or modify credentials for users of the CredHub Service.
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Analysis
by VulDB Data Team • 06/06/2023
The vulnerability identified as CVE-2018-15795 affects Pivotal CredHub Service Broker versions prior to 1.1.0, representing a critical weakness in the service broker's authentication mechanism that undermines the security of credential management within cloud environments. This flaw resides in the implementation of random number generation used for creating UAA (User Account and Authentication) client secrets, which are essential components for secure service broker operations. The issue stems from the use of predictable or guessable random number generation methods that fail to provide adequate entropy for cryptographic security purposes.
The technical flaw manifests in the service broker's inability to generate sufficiently random client secrets for UAA authentication, creating a scenario where malicious actors can potentially predict or guess the client secret values through statistical analysis or pattern recognition. This vulnerability directly impacts the confidentiality and integrity of credential management systems by allowing unauthorized access to sensitive user credentials stored within CredHub. The weakness enables attackers to impersonate legitimate service broker clients and gain unauthorized access to credential data, potentially leading to privilege escalation and data breaches within the cloud infrastructure. The vulnerability aligns with CWE-330, which addresses insufficient entropy in random number generation, and represents a classic example of poor cryptographic implementation that violates fundamental security principles.
From an operational standpoint, this vulnerability presents significant risks to organizations utilizing Pivotal CredHub Service Broker in production environments, as it allows remote attackers to obtain or modify credentials for users of the service broker. The impact extends beyond simple credential theft to include potential service disruption, unauthorized access to cloud resources, and compromise of the entire credential management ecosystem. Attackers exploiting this vulnerability can manipulate user credentials, potentially gaining access to sensitive applications and data stored within the CredHub service. The attack surface is particularly concerning in multi-tenant cloud environments where credential compromise could affect multiple users and applications simultaneously, making this vulnerability a high-priority concern for cloud security teams.
Organizations should implement immediate mitigations including upgrading to Pivotal CredHub Service Broker version 1.1.0 or later, which contains the necessary fixes for the random number generation implementation. Security teams must also conduct thorough assessments of existing UAA client secrets and regenerate those that may have been compromised, following the principle of least privilege and regular credential rotation. The mitigation strategy should incorporate comprehensive monitoring for unauthorized access attempts and implement additional authentication controls such as multi-factor authentication for service broker operations. Organizations should also consider implementing network segmentation and access controls to limit exposure of the service broker components, aligning with ATT&CK technique T1078 for valid accounts and T1566 for credential access through service broker exploitation. The vulnerability underscores the critical importance of proper cryptographic implementation and random number generation in security-critical applications, particularly in cloud service broker environments where credential management is paramount to overall system security.