CVE-2021-22148 in Enterprise Search App
Summary
by MITRE • 09/15/2021
Elastic Enterprise Search App Search versions before 7.14.0 was vulnerable to an issue where API keys were not bound to the same engines as their creator. This could lead to a less privileged user gaining access to unauthorized engines.
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Analysis
by VulDB Data Team • 09/19/2021
Elastic Enterprise Search App Search versions prior to 7.14.0 contained a critical access control vulnerability that fundamentally compromised the security boundaries between user permissions and engine access. This vulnerability originated from a design flaw in the API key management system where authentication tokens were not properly constrained to the specific search engines they were intended to access. The issue created a privilege escalation scenario where users with minimal permissions could potentially exploit the misconfigured access controls to retrieve data from engines they should not have authorization to view.
The technical flaw manifested as a failure in the API key binding mechanism that should have enforced strict correlation between user credentials and engine contexts. When API keys were generated within the App Search framework, the system failed to maintain proper association between the key and the specific engine or set of engines for which it was authorized. This resulted in a scenario where an attacker could take a valid API key created for one engine and use it to access data from other engines within the same deployment, effectively bypassing the intended access controls. The vulnerability represented a direct violation of the principle of least privilege and demonstrated a critical breakdown in the authorization model.
The operational impact of this vulnerability extended beyond simple unauthorized data access, as it enabled potential attackers to perform reconnaissance activities across multiple engines within a single deployment. An attacker with access to a low-privilege API key could enumerate and extract information from engines they should not be able to reach, potentially leading to data leakage, information disclosure, and service disruption. This vulnerability particularly affected organizations that relied on App Search for multi-tenant environments or applications where different teams or clients shared the same deployment but required isolated access to their respective data sources.
Organizations implementing Elastic Enterprise Search App Search should have immediately upgraded to version 7.14.0 or later to remediate this vulnerability, as the flaw existed in the core access control mechanisms of the platform. The fix implemented in version 7.14.0 addressed the binding issue by ensuring that API keys are properly constrained to the engines for which they were created, preventing cross-engine access through API tokens. Security teams should have conducted immediate assessments of their App Search deployments to identify any potential exploitation attempts and reviewed access logs for unusual patterns of engine enumeration. This vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK technique T1078 Valid Accounts, as it allowed unauthorized access through legitimate API keys. The remediation process should have included comprehensive testing of access controls and verification that API keys could no longer be used to access unauthorized engines, ensuring proper isolation between different data contexts within the App Search platform.