CVE-2012-5563 in Folsom
Summary
by MITRE
OpenStack Keystone, as used in OpenStack Folsom 2012.2, does not properly implement token expiration, which allows remote authenticated users to bypass intended authorization restrictions by creating new tokens through token chaining. NOTE: this issue exists because of a CVE-2012-3426 regression.
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Analysis
by VulDB Data Team • 12/20/2021
The vulnerability identified as CVE-2012-5563 affects OpenStack Keystone authentication service within the OpenStack Folsom 2012.2 release, representing a critical authorization bypass flaw that undermines the security model of cloud infrastructure deployments. This issue specifically targets the token expiration implementation within Keystone, which serves as the central authentication service for OpenStack environments. The vulnerability arises from a regression introduced by CVE-2012-3426, demonstrating how security fixes can inadvertently create new attack vectors when not thoroughly validated across the entire system architecture. Organizations relying on OpenStack for cloud computing services faced significant risks as this flaw allowed malicious actors to extend their access beyond intended time limits through legitimate authentication mechanisms.
The technical flaw manifests in Keystone's improper handling of token expiration mechanisms, specifically enabling authenticated users to perform token chaining attacks that create new valid tokens without proper authorization checks. This occurs because the system fails to properly validate token expiration status when processing token requests, allowing attackers to leverage existing valid tokens to generate additional tokens that maintain the same privileges and access levels. The vulnerability operates at the authentication layer where token lifecycle management is compromised, creating a persistent access vector that bypasses normal session timeout protections. This represents a direct violation of the principle of least privilege and undermines the fundamental security assumptions of the authentication system.
Operationally, this vulnerability enables remote authenticated attackers to maintain prolonged access to cloud resources beyond their intended expiration periods, effectively creating persistent backdoors within cloud environments. The impact extends beyond simple privilege escalation to include potential data exfiltration, system compromise, and unauthorized resource consumption across the entire OpenStack deployment. Attackers can exploit this flaw to extend their access indefinitely by continuously creating new tokens from existing valid ones, making detection and mitigation particularly challenging. The vulnerability affects all authenticated users within the system, regardless of their initial privileges, making it especially dangerous in multi-tenant cloud environments where isolation between users is critical for security.
Mitigation strategies for CVE-2012-5563 require immediate patching of the OpenStack Keystone service to address the token expiration regression, with organizations implementing comprehensive monitoring of token creation and usage patterns. System administrators should enforce strict token lifecycle management policies and implement additional authentication controls such as multi-factor authentication to reduce the impact of potential exploitation. The fix addresses the underlying CWE-284 weakness related to improper access control and aligns with ATT&CK technique T1550.001 for valid accounts and T1550.002 for use of stolen credentials, emphasizing the importance of proper session management and token validation. Organizations should also conduct thorough security assessments of their cloud infrastructure to identify any other potential regressions or similar vulnerabilities in their OpenStack deployments.