CVE-2014-3621 in Keystone
Summary
by MITRE
The catalog url replacement in OpenStack Identity (Keystone) before 2013.2.3 and 2014.1 before 2014.1.2.1 allows remote authenticated users to read sensitive configuration options via a crafted endpoint, as demonstrated by "$(admin_token)" in the publicurl endpoint field.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 03/29/2022
The vulnerability identified as CVE-2014-3621 represents a critical configuration exposure within OpenStack Identity service Keystone, specifically affecting versions prior to 2013.2.3 and 2014.1.2.1. This flaw resides in the catalog URL replacement mechanism that processes endpoint URLs during service registration and catalog generation. The vulnerability stems from insufficient input validation and sanitization of endpoint fields, particularly the publicurl parameter, which allows attackers to inject arbitrary configuration variables that are then processed and exposed to authenticated users. The specific exploitation vector involves crafting malicious endpoint data containing variable substitution patterns such as "$(admin_token)" which are then interpreted and rendered in the service catalog, potentially exposing sensitive administrative credentials and configuration parameters.
The technical implementation of this vulnerability exploits a fundamental flaw in how Keystone handles endpoint URL templating and variable substitution within its service catalog generation process. When Keystone processes service endpoints, it performs string replacement operations on URL templates without adequate sanitization of user-provided input. This creates a path traversal and information disclosure scenario where authenticated users can manipulate endpoint registration to inject configuration variables that are subsequently exposed in the service catalog responses. The vulnerability operates at the application layer and requires only authenticated access, making it particularly dangerous as it can be exploited by users with minimal privileges who can then escalate their access by extracting sensitive administrative tokens and configuration data. This weakness directly maps to CWE-20: Improper Input Validation and CWE-22: Improper Limitation of a Pathname to a Restricted Directory, as it allows unauthorized data exposure through improper handling of user-supplied endpoint data.
The operational impact of CVE-2014-3621 extends beyond simple information disclosure to create potential privilege escalation pathways within OpenStack environments. Attackers who can authenticate to Keystone can leverage this vulnerability to extract administrative tokens, service credentials, and other sensitive configuration parameters that are typically protected from regular users. This exposure enables adversaries to gain deeper insights into the cloud infrastructure, potentially allowing them to craft more sophisticated attacks against other services within the OpenStack ecosystem. The vulnerability is particularly concerning in multi-tenant environments where different users share the same Keystone service, as it could allow one user to access another user's service credentials or administrative information. The attack chain typically involves registering a malicious endpoint with crafted URL templates, then accessing the service catalog to retrieve the exposed sensitive data, which can then be used for further exploitation within the cloud environment.
Mitigation strategies for CVE-2014-3621 focus primarily on upgrading to patched versions of OpenStack Keystone where proper input sanitization and validation have been implemented. Organizations should immediately update their Keystone deployments to versions 2013.2.3 or 2014.1.2.1 and later, which contain the necessary security fixes. Additionally, administrators should implement strict endpoint validation policies that prevent the registration of endpoints containing variable substitution patterns or other potentially dangerous templates. Network segmentation and access control measures should be strengthened to limit the scope of authenticated users who can register or modify service endpoints. The implementation of principle of least privilege should be enforced, ensuring that only trusted administrators have the ability to register new endpoints or modify existing ones. Organizations should also monitor service catalog responses for unusual patterns and implement logging controls that track endpoint registration activities to detect potential exploitation attempts. This vulnerability aligns with ATT&CK technique T1566.002: Phishing via Service Provider and T1566.001: Phishing, as it can be exploited through crafted endpoint registration to gain unauthorized access to sensitive configuration data that would otherwise be protected within the cloud infrastructure.