CVE-2018-10936 in postgresql-jdbc
Summary
by MITRE
A weakness was found in postgresql-jdbc before version 42.2.5. It was possible to provide an SSL Factory and not check the host name if a host name verifier was not provided to the driver. This could lead to a condition where a man-in-the-middle attacker could masquerade as a trusted server by providing a certificate for the wrong host, as long as it was signed by a trusted CA.
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Analysis
by VulDB Data Team • 05/06/2023
The vulnerability identified as CVE-2018-10936 represents a critical security flaw in the PostgreSQL JDBC driver affecting versions prior to 42.2.5. This weakness stems from insufficient SSL certificate validation mechanisms within the driver's implementation, creating a significant attack surface that adversaries could exploit to conduct man-in-the-middle attacks against database connections. The issue specifically impacts applications that rely on the JDBC driver for PostgreSQL database connectivity and establishes a dangerous precedent where cryptographic security measures fail to properly validate server identity even when SSL/TLS encryption is enabled.
The technical flaw manifests in the driver's handling of SSL certificate validation when an SSL factory is explicitly provided but no hostname verifier is configured. According to the Common Weakness Enumeration standard CWE-295, this vulnerability falls under the category of "Improper Certificate Validation" where the system fails to properly verify that the certificate presented by the server matches the expected host. The PostgreSQL JDBC driver's implementation allows for a scenario where the SSL handshake can succeed even when the certificate is issued for a different host than the one the client is attempting to connect to, as long as the certificate is signed by a trusted certificate authority. This creates a fundamental breakdown in the trust model that SSL/TLS is designed to establish between client and server.
The operational impact of this vulnerability extends beyond simple data interception, as it enables sophisticated attack vectors that can compromise database integrity and confidentiality. Attackers can exploit this weakness by setting up malicious servers that present valid certificates from trusted CAs but for incorrect hostnames, effectively bypassing the certificate validation process entirely. This vulnerability aligns with ATT&CK technique T1566.001 which describes "Phishing: Spearphishing Attachment" but in the context of network infrastructure rather than email attachments, where the attack targets the underlying connection security rather than user interaction. Organizations using affected versions of the PostgreSQL JDBC driver face significant risk of unauthorized access to their database systems, potentially leading to data breaches, privilege escalation, and complete system compromise.
Mitigation strategies for this vulnerability require immediate patching of the PostgreSQL JDBC driver to version 42.2.5 or later, which implements proper hostname verification mechanisms. Security administrators should also implement additional network-level protections such as firewall rules that restrict database access to trusted IP addresses and consider implementing network segmentation to limit the potential impact of successful attacks. The fix addresses the root cause by ensuring that when an SSL factory is provided, the driver automatically enforces hostname verification unless explicitly disabled by the application configuration. Organizations should also review their database connection configurations to ensure that all SSL connections are properly validated and that applications are not inadvertently bypassing security checks through improper configuration of SSL parameters. This vulnerability demonstrates the critical importance of proper cryptographic implementation and the necessity of comprehensive security testing for all network communication components in enterprise environments.