CVE-2020-10706 in Container Platform
Summary
by MITRE
A flaw was found in OpenShift Container Platform where OAuth tokens are not encrypted when the encryption of data at rest is enabled. This flaw allows an attacker with access to a backup to obtain OAuth tokens and then use them to log into the cluster as any user who logged into the cluster via the WebUI or via the command line in the last 24 hours. Once the backup is older than 24 hours the OAuth tokens are no longer valid.
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Analysis
by VulDB Data Team • 10/16/2020
The vulnerability identified as CVE-2020-10706 represents a critical security flaw in the OpenShift Container Platform that fundamentally undermines the integrity of the authentication system. This issue manifests when the platform's data at rest encryption feature is enabled, creating a dangerous inconsistency in how sensitive authentication data is handled. The flaw specifically affects OAuth tokens which are designed to provide secure access to cluster resources but are stored in an unencrypted state despite the overall encryption configuration being active. This creates a significant attack surface where adversaries can exploit the backup data to gain unauthorized access to cluster resources. The vulnerability is particularly concerning because it directly contradicts the expected security posture that data at rest encryption should protect all sensitive information within the system, including authentication credentials that are essential for maintaining cluster integrity and access control.
The technical implementation flaw stems from the improper handling of OAuth token storage within the backup and restore mechanisms of OpenShift. When administrators enable data at rest encryption, they expect all sensitive data to be protected through encryption, but this vulnerability demonstrates that OAuth tokens are being stored in plaintext format within backup files. This creates a scenario where any individual with access to backup data can extract these tokens without requiring additional cryptographic keys or authentication factors. The flaw operates through the backup restoration process where OAuth tokens are not properly encrypted even when the system encryption is active, effectively creating a backdoor that bypasses normal authentication security controls. This issue is classified under CWE-312 (Cleartext Storage of Sensitive Information) and represents a failure in proper data protection implementation that violates fundamental security principles.
The operational impact of this vulnerability is severe and far-reaching for OpenShift cluster administrators and security teams. An attacker with access to backup files can immediately obtain valid OAuth tokens that remain functional for 24 hours after the last user authentication, regardless of the user's privileges or roles within the cluster. This timeframe provides ample opportunity for unauthorized access to cluster resources, potentially enabling privilege escalation attacks, data exfiltration, and persistent access to the environment. The 24-hour validity window creates a temporal attack vector where attackers can exploit this vulnerability even after the initial backup creation, making it particularly dangerous for environments where backups are stored in potentially insecure locations or accessed by unauthorized personnel. This vulnerability directly impacts the principle of least privilege and can allow attackers to impersonate legitimate users with full access rights to cluster resources, including the ability to deploy applications, modify configurations, and access sensitive data.
Organizations should implement immediate mitigations to address this vulnerability by ensuring that OAuth tokens are properly encrypted even when backup systems are in use. The recommended approach involves implementing additional encryption layers specifically for authentication tokens, regardless of the overall data at rest encryption status. Security teams should also establish strict access controls for backup storage locations, ensuring that only authorized personnel can access backup data and that these systems are protected with multi-factor authentication. Regular monitoring of backup access logs and implementing automated alerts for unauthorized backup access attempts can help detect potential exploitation attempts. The vulnerability highlights the importance of comprehensive security testing that includes backup and restore scenarios to ensure that all sensitive data is properly protected throughout the entire data lifecycle. Organizations should also consider implementing token rotation mechanisms that reduce the window of opportunity for attackers to exploit stolen tokens and ensure that backup systems are regularly audited for proper encryption implementation. This vulnerability serves as a reminder that security controls must be applied consistently across all data handling processes, including backup and restore operations, to prevent the exposure of sensitive information through seemingly secure configurations.