CVE-2013-2104 in python-keystoneclient
Summary
by MITRE
python-keystoneclient before 0.2.4, as used in OpenStack Keystone (Folsom), does not properly check expiry for PKI tokens, which allows remote authenticated users to (1) retain use of a token after it has expired, or (2) use a revoked token once it expires.
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Analysis
by VulDB Data Team • 01/31/2022
The vulnerability identified as CVE-2013-2104 affects the python-keystoneclient library version 0.2.3 and earlier, which is utilized within OpenStack Keystone Folsom release. This security flaw resides in the token validation mechanism specifically concerning PKI (Public Key Infrastructure) tokens used for authentication within cloud environments. The issue stems from improper token expiry validation that creates persistent security weaknesses in the authentication system. The vulnerability is particularly concerning because it directly impacts the core authentication and authorization mechanisms that protect cloud infrastructure resources. When a token expires or gets revoked, the system should immediately invalidate its usage, but this flaw allows attackers to circumvent these security controls through legitimate authenticated access.
The technical implementation flaw involves the failure to properly validate token expiration timestamps during authentication requests. PKI tokens in OpenStack Keystone contain cryptographic signatures along with expiration metadata that should be rigorously checked upon each authentication attempt. However, the vulnerable implementation does not adequately verify that tokens have not exceeded their validity period or that revoked tokens are properly rejected after their expiration time. This oversight creates a window of opportunity where authenticated users can continue utilizing tokens beyond their intended lifespan or exploit revoked tokens until they naturally expire. The flaw essentially bypasses the token lifecycle management that should enforce strict time-based access controls and revocation policies.
The operational impact of this vulnerability extends beyond simple authentication bypasses and presents significant risks to cloud security postures. Attackers who gain authenticated access to the system can maintain persistent access to cloud resources even after their tokens should have expired or been revoked, effectively extending their unauthorized access period. This weakness undermines the fundamental principle of time-based credential expiration that is essential for minimizing the impact of compromised credentials. Additionally, the vulnerability can be exploited to maintain access to sensitive cloud infrastructure even when administrators have attempted to revoke compromised tokens, creating a false sense of security during incident response activities. The persistence of access through expired or revoked tokens can enable extended data exfiltration, privilege escalation, or other malicious activities without immediate detection.
The vulnerability aligns with CWE-284, which addresses inadequate access control mechanisms, and can be mapped to ATT&CK techniques related to privilege escalation and persistence. Organizations using affected versions of OpenStack Keystone should immediately implement mitigation strategies including updating to python-keystoneclient version 0.2.4 or later, which contains the necessary token validation fixes. Additional protective measures include implementing robust monitoring for unusual token usage patterns, enforcing strict token lifecycle management policies, and conducting regular security audits of authentication systems. System administrators should also consider implementing token rotation mechanisms and enhanced logging of authentication events to detect potential exploitation of this vulnerability. The fix addresses the core validation logic to ensure that token expiration and revocation status are properly enforced during all authentication requests, thereby restoring the intended security controls for cloud access management.