CVE-2021-43767 in Odyssey
Summary
by MITRE • 08/25/2022
Odyssey passes to client unencrypted bytes from man-in-the-middle When Odyssey storage is configured to use the PostgreSQL server using 'trust' authentication with a 'clientcert' requirement or to use 'cert' authentication, a man-in-the-middle attacker can inject false responses to the client's first few queries. Despite the use of SSL certificate verification and encryption, Odyssey will pass these results to client as if they originated from valid server. This is similar to CVE-2021-23222 for PostgreSQL.
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Analysis
by VulDB Data Team • 10/02/2022
The vulnerability identified as CVE-2021-43767 affects Odyssey, a PostgreSQL connection pooler and proxy software that operates between client applications and PostgreSQL database servers. This security flaw represents a critical issue in the authentication and encryption handling mechanisms of Odyssey, specifically when configured to use PostgreSQL's trust authentication method combined with client certificate requirements or certificate-based authentication. The vulnerability creates a window of opportunity for man-in-the-middle attacks that exploit the trust relationship between Odyssey and PostgreSQL servers, allowing attackers to inject malicious responses during the initial connection phase before proper authentication and encryption are fully established.
The technical flaw stems from Odyssey's handling of the initial authentication handshake process when PostgreSQL servers are configured with trust authentication alongside client certificate requirements. During the connection establishment phase, Odyssey attempts to validate the server's SSL certificate and establish secure communication channels. However, the software fails to properly validate or sanitize responses received from the PostgreSQL server during this initial phase, particularly when the server requires client certificates. This creates a scenario where an attacker positioned between Odyssey and the PostgreSQL server can intercept and inject false responses to the client's first few queries, bypassing the normal encryption and certificate verification mechanisms that should protect against such attacks.
The operational impact of this vulnerability is significant for organizations using Odyssey in production environments, particularly those implementing strict PostgreSQL authentication policies that rely on client certificates. When an attacker successfully exploits this vulnerability, they can manipulate database communications and potentially gain unauthorized access to database resources, execute arbitrary queries, or compromise the integrity of database transactions. The attack vector is particularly dangerous because it leverages the trust relationship that exists between Odyssey and PostgreSQL servers, making it difficult for traditional network monitoring tools to detect the malicious activity. This vulnerability affects organizations that implement PostgreSQL trust authentication with client certificate requirements as part of their security posture, potentially undermining their entire database security framework.
Organizations should immediately implement mitigations including updating to the latest version of Odyssey where this vulnerability has been addressed, reviewing and modifying PostgreSQL server configurations to avoid using trust authentication combined with client certificate requirements, and implementing additional network security controls such as strict firewall rules and network segmentation. The vulnerability aligns with CWE-295 which deals with improper certificate validation, and relates to ATT&CK technique T1071.004 for application layer protocol manipulation. Additional defensive measures should include implementing comprehensive network monitoring for unusual authentication patterns, deploying intrusion detection systems specifically configured to detect man-in-the-middle attack signatures, and establishing robust certificate management processes that ensure proper validation of SSL certificates throughout the connection lifecycle.
This vulnerability demonstrates the critical importance of proper input validation and response sanitization in network proxy software, particularly when dealing with authentication and encryption protocols. The flaw highlights the need for comprehensive security testing of connection pooling and proxy software in complex authentication scenarios, as well as the necessity of implementing defense-in-depth strategies that protect against multiple attack vectors simultaneously. Organizations should also consider implementing additional verification mechanisms beyond standard SSL certificate validation to ensure that all communications between Odyssey and PostgreSQL servers are properly authenticated and encrypted throughout the entire connection lifecycle, preventing similar vulnerabilities from affecting their database infrastructure.