CVE-2016-4950 in Manager
Summary
by MITRE
Cloudera Manager 5.5 and earlier allows remote attackers to enumerate user sessions via a request to /api/v11/users/sessions.
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Analysis
by VulDB Data Team • 09/04/2020
Cloudera Manager version 5.5 and earlier contains a critical information disclosure vulnerability that enables remote attackers to enumerate user sessions through a specific API endpoint. This vulnerability resides within the web application's session management mechanism and exposes sensitive session information to unauthorized parties. The affected endpoint /api/v11/users/sessions provides an interface that should typically be restricted to authorized administrators or authenticated users with appropriate privileges, but instead reveals session data to any remote attacker who can access the API. This flaw represents a significant security weakness in Cloudera's authentication and authorization framework, as it allows adversaries to gather intelligence about active user sessions without proper authentication credentials.
The technical implementation of this vulnerability stems from inadequate access control measures within the Cloudera Manager's API architecture. When a remote attacker sends a request to the /api/v11/users/sessions endpoint, the system fails to properly validate the requester's authorization level or authentication status. This design flaw allows the system to return session information including session identifiers, user accounts, and potentially other metadata about active connections. The vulnerability can be exploited through simple HTTP requests and does not require any special privileges or authentication tokens to initiate the enumeration process. The exposed session data could include session IDs, user names, connection timestamps, and potentially IP addresses associated with active sessions, providing attackers with valuable information for further exploitation attempts.
The operational impact of this vulnerability extends beyond simple information disclosure, creating potential pathways for more sophisticated attacks within the Cloudera environment. Attackers who successfully enumerate user sessions can use this information to conduct targeted attacks such as session hijacking, where they attempt to impersonate legitimate users by stealing active session tokens. This vulnerability also enables reconnaissance activities where attackers can identify active users, determine system usage patterns, and potentially map out user access privileges within the Cloudera Manager environment. The exposure of session data can facilitate credential stuffing attacks against other systems where users may have reused passwords, or provide attackers with insights into user behavior and system access times. Additionally, this information can be leveraged for privilege escalation attempts if the session data reveals administrative access levels or sensitive user roles within the system.
Organizations using Cloudera Manager 5.5 or earlier versions should immediately implement mitigations to address this vulnerability. The primary recommendation involves upgrading to a patched version of Cloudera Manager that properly enforces access controls on the session enumeration endpoint. Security administrators should also implement network-level restrictions to limit access to the affected API endpoints, particularly from untrusted networks. Additional mitigations include enabling robust authentication mechanisms, implementing proper API rate limiting to prevent automated enumeration attempts, and monitoring for suspicious access patterns to the /api/v11/users/sessions endpoint. Organizations should conduct comprehensive security assessments to identify any other similar access control weaknesses within their Cloudera Manager installations and consider implementing web application firewalls to detect and block malicious requests targeting this vulnerability. The vulnerability aligns with CWE-284, which describes inadequate access control, and can be mapped to ATT&CK technique T1565.001 for credential dumping and session hijacking activities.
This vulnerability demonstrates the critical importance of proper access control implementation in enterprise management systems and highlights how seemingly minor security oversights can create significant exposure points. The flaw represents a classic example of insufficient input validation and access control enforcement within web applications, where the system fails to properly authenticate and authorize API requests before returning sensitive information. Organizations should treat this vulnerability as a high-priority issue requiring immediate remediation, as it provides attackers with the foundational information needed to conduct more sophisticated attacks against the Cloudera Manager infrastructure. The exposed session enumeration capability creates a persistent threat vector that can be exploited repeatedly, making it essential for security teams to implement both immediate fixes and long-term monitoring solutions to prevent unauthorized access to session information.