CVE-2023-31007 in Pulsar
Summary
by MITRE • 07/12/2023
Improper Authentication vulnerability in Apache Software Foundation Apache Pulsar Broker allows a client to stay connected to a broker after authentication data expires if the client connected through the Pulsar Proxy when the broker is configured with authenticateOriginalAuthData=false or if a client connects directly to a broker with a specially crafted connect command when the broker is configured with authenticateOriginalAuthData=false. This issue affects Apache Pulsar: through 2.9.4, from 2.10.0 through 2.10.3, 2.11.0. 2.9 Pulsar Broker users should upgrade to at least 2.9.5. 2.10 Pulsar Broker users should upgrade to at least 2.10.4. 2.11 Pulsar Broker users should upgrade to at least 2.11.1. 3.0 Pulsar Broker users are unaffected. Any users running the Pulsar Broker for 2.8.* and earlier should upgrade to one of the above patched versions.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/30/2023
The CVE-2023-31007 vulnerability represents a critical improper authentication flaw within Apache Pulsar Broker systems that fundamentally undermines the security posture of message streaming platforms. This vulnerability specifically targets the authentication mechanisms within Apache Pulsar's architecture, where client sessions can persist beyond their intended expiration periods under certain configuration conditions. The flaw manifests when brokers are configured with authenticateOriginalAuthData=false, creating a window of opportunity for unauthorized access that persists even after legitimate authentication credentials have expired. This issue affects multiple versions of the Apache Pulsar platform, spanning from version 2.9.4 through 2.10.3 and including 2.11.0, making it a widespread concern for organizations relying on these messaging systems. The vulnerability is particularly concerning because it operates at the core of Pulsar's security model, where the fundamental principle of time-bound authentication is violated, allowing potentially malicious actors to maintain access to broker resources beyond their authorized duration.
The technical implementation of this vulnerability stems from how Pulsar handles authentication data when the authenticateOriginalAuthData parameter is set to false. Under normal circumstances, this setting should not impact authentication flow, but in this specific case, it creates a condition where expired authentication tokens can still be accepted for continued communication. When clients connect through the Pulsar Proxy or directly to brokers using specially crafted connection commands, the system fails to properly validate that authentication credentials are still valid. This flaw is categorized as a CWE-287 Improper Authentication weakness, which directly relates to the failure of systems to properly verify the identity of users or systems attempting to access protected resources. The vulnerability operates at the network protocol level within Pulsar's broker architecture, where connection management and authentication state transitions are not properly synchronized, allowing session persistence despite credential expiration. This misconfiguration creates a persistent security gap that can be exploited by attackers who have already established initial access to the system.
The operational impact of CVE-2023-31007 extends far beyond simple access control violations, as it creates potential for data exfiltration, message manipulation, and system compromise within affected Pulsar deployments. Organizations running vulnerable versions face the risk of unauthorized data access, where malicious actors can maintain persistent connections to broker services even after their original authentication tokens have expired. This vulnerability particularly affects environments where Pulsar is used for sensitive data processing, as it allows attackers to potentially intercept, modify, or delete messages without detection. The impact is amplified when considering that Pulsar is commonly deployed in enterprise environments where it handles critical business data flows, making this vulnerability a significant concern for compliance and security auditing. Attackers could leverage this flaw to maintain long-term access to messaging systems, potentially enabling advanced persistent threat scenarios where they can monitor data flows, inject malicious messages, or disrupt service availability. The vulnerability also creates challenges for security monitoring and incident response, as legitimate access patterns may be obscured by the continued operation of expired sessions.
Mitigation strategies for CVE-2023-31007 require immediate attention and systematic implementation across affected Pulsar deployments. The primary and most effective mitigation is upgrading to the patched versions specified by Apache Pulsar, with version 2.9.5, 2.10.4, and 2.11.1 being the minimum recommended releases for each respective version line. Organizations should also consider implementing additional monitoring and alerting mechanisms to detect anomalous connection patterns that might indicate exploitation attempts. Security teams should review their current Pulsar configurations to ensure that authenticateOriginalAuthData is properly set according to their security requirements, and implement regular configuration audits to prevent unauthorized changes. The ATT&CK framework categorizes this vulnerability under T1078 Valid Accounts and T1566 Phishing, as it allows attackers to maintain access using legitimate credentials, making it particularly difficult to detect through conventional security monitoring. Organizations should also implement network segmentation and access controls to limit the blast radius of potential exploitation, ensuring that even if a client session is compromised, the attacker's access remains restricted to specific areas of the messaging infrastructure. Additionally, implementing comprehensive logging of authentication events and session management activities will provide crucial forensic data for incident response and security analysis.