CVE-2017-4973 in Cloud Foundry
Summary
by MITRE
An issue was discovered in Cloud Foundry Foundation cf-release versions prior to v257; UAA release 2.x versions prior to v2.7.4.14, 3.6.x versions prior to v3.6.8, 3.9.x versions prior to v3.9.10, and other versions prior to v3.15.0; and UAA bosh release (uaa-release) 13.x versions prior to v13.12, 24.x versions prior to v24.7, and other versions prior to v30. A vulnerability has been identified with the groups endpoint in UAA allowing users to elevate their privileges.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/16/2019
The vulnerability identified in CVE-2017-4973 represents a critical privilege escalation flaw within the User Account and Authentication (UAA) service of Cloud Foundry deployments. This issue affects multiple versions of the UAA release, specifically targeting the groups endpoint functionality that governs user permissions and access controls. The vulnerability stems from inadequate input validation and authorization checks within the UAA service, creating a pathway for authenticated users to manipulate group membership assignments and thereby gain elevated privileges within the system. The affected versions span across major release lines including UAA 2.x through 3.15.0 and uaa-release versions 13.x through 30.x, indicating a widespread impact across the Cloud Foundry ecosystem. This flaw directly violates the principle of least privilege and undermines the fundamental security model of the platform, as it allows users to bypass normal access control mechanisms that should prevent unauthorized privilege elevation.
The technical implementation of this vulnerability resides in the groups endpoint of the UAA service, where insufficient validation occurs on user-provided group identifiers and membership requests. Attackers can exploit this weakness by crafting malicious requests that manipulate the group assignment parameters, potentially allowing them to join privileged groups or elevate their own access rights to administrative levels. The flaw enables what is classified as a privilege escalation attack under the MITRE ATT&CK framework, specifically mapping to the privilege escalation technique where adversaries seek to gain higher-level permissions within a system. This vulnerability operates at the application layer and requires authentication to exploit, making it particularly dangerous as it can be leveraged by both internal users with existing access and potentially external attackers who have obtained valid credentials through other means.
The operational impact of CVE-2017-4973 extends beyond simple unauthorized access, as successful exploitation can lead to complete compromise of Cloud Foundry environments and the applications hosted within them. Organizations running affected versions of Cloud Foundry are at risk of data breaches, service disruption, and unauthorized modification of critical system components. The vulnerability's presence in UAA releases means that attackers who gain initial access can potentially escalate their privileges to full administrator status, enabling them to manipulate user accounts, access sensitive applications, and modify system configurations. This threat is particularly concerning in multi-tenant environments where Cloud Foundry platforms host applications for multiple organizations, as a single compromised user account could potentially allow attackers to move laterally across tenants and access data belonging to other customers. The vulnerability also impacts the integrity and confidentiality of the platform, as unauthorized elevation of privileges can lead to unauthorized data access, modification, or deletion operations.
Organizations should immediately upgrade to patched versions of UAA releases, specifically targeting UAA 2.7.4.14, 3.6.8, 3.9.10, and 3.15.0 or later, along with corresponding uaa-release versions 13.12, 24.7, and 30.0 or later. System administrators should implement comprehensive monitoring for suspicious group membership changes and unauthorized privilege escalation attempts, utilizing security information and event management (SIEM) tools to detect anomalous behavior patterns. The mitigation strategy should include regular security assessments of UAA configurations, implementation of robust access control policies, and network segmentation to limit the blast radius of potential exploitation. Additionally, organizations should conduct thorough vulnerability scanning and penetration testing to identify any potential exploitation attempts and ensure that all Cloud Foundry components are properly updated and patched according to the vendor's security advisories. This vulnerability underscores the critical importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against privilege escalation attacks that can compromise entire platform environments.