CVE-2016-3703 in OpenShift Enterprise
Summary
by MITRE
Red Hat OpenShift Enterprise 3.2 and 3.1 do not properly validate the origin of a request when anonymous access is granted to a service/proxy or pod/proxy API for a specific pod, which allows remote attackers to access API credentials in the web browser localStorage via an access_token in the query parameter.
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Analysis
by VulDB Data Team • 08/23/2022
The vulnerability identified as CVE-2016-3703 affects Red Hat OpenShift Enterprise versions 3.1 and 3.2, representing a critical authorization flaw that undermines the security posture of container orchestration platforms. This issue stems from improper validation of request origins when anonymous access is granted to service or pod proxies, creating a dangerous pathway for unauthorized access to sensitive API credentials stored in web browser client-side storage mechanisms. The flaw specifically manifests when attackers can manipulate query parameters to access access_token values that are inadvertently stored in localStorage, bypassing intended authentication mechanisms and potentially compromising the entire containerized application ecosystem.
The technical implementation of this vulnerability exploits a fundamental weakness in the cross-origin resource sharing validation logic within the OpenShift proxy components. When anonymous access is enabled for specific pods or services, the system fails to properly verify the origin of incoming requests, allowing malicious actors to craft requests that leverage existing access tokens stored in the browser's localStorage. This represents a classic case of insufficient origin validation, where the system assumes that legitimate requests originate from authorized sources without proper verification. The vulnerability is particularly concerning because it operates at the web application layer, where the attack surface includes not just the backend services but also the client-side browser components that store authentication tokens. The flaw essentially creates a pathway for attackers to harvest access tokens from the browser's localStorage through carefully crafted requests that bypass normal authentication checks, enabling them to impersonate legitimate users or services within the container environment.
From an operational impact perspective, this vulnerability exposes organizations to significant security risks including unauthorized access to containerized applications, potential data breaches, and privilege escalation within the OpenShift environment. Attackers can leverage this flaw to access sensitive API credentials that may grant them access to other services, pods, or even underlying infrastructure components that are protected by the same authentication mechanisms. The vulnerability affects the core security model of OpenShift by undermining the trust boundary between the user interface and the backend services, potentially allowing attackers to move laterally within the containerized environment. This represents a serious concern for organizations using OpenShift for production workloads, as it could enable attackers to access sensitive data, modify application configurations, or even take control of containerized applications that are protected by the platform's authentication mechanisms.
Mitigation strategies for CVE-2016-3703 should focus on implementing proper origin validation mechanisms and strengthening the security of client-side credential storage. Organizations should immediately update to patched versions of Red Hat OpenShift Enterprise that address the origin validation flaw, while also implementing additional security controls such as strict Content Security Policy headers to prevent unauthorized access to localStorage. The implementation of proper token management practices, including the use of short-lived access tokens and secure storage mechanisms, can help reduce the impact of such vulnerabilities. Security teams should also consider implementing monitoring for suspicious request patterns and unauthorized access attempts, as well as conducting regular security assessments of containerized environments to identify similar authorization flaws. This vulnerability aligns with CWE-346, which addresses improper verification of data source, and maps to ATT&CK technique T1566 for credential access through web application vulnerabilities, highlighting the need for comprehensive security controls that address both the immediate flaw and broader application security weaknesses in containerized environments.