CVE-2017-7485 in PostgreSQL
Summary
by MITRE
In PostgreSQL 9.3.x before 9.3.17, 9.4.x before 9.4.12, 9.5.x before 9.5.7, and 9.6.x before 9.6.3, it was found that the PGREQUIRESSL environment variable was no longer enforcing a SSL/TLS connection to a PostgreSQL server. An active Man-in-the-Middle attacker could use this flaw to strip the SSL/TLS protection from a connection between a client and a server.
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Analysis
by VulDB Data Team • 09/07/2025
The vulnerability identified as CVE-2017-7485 represents a critical security flaw in PostgreSQL database systems affecting multiple version branches including 9.3.x through 9.3.16, 9.4.x through 9.4.11, 9.5.x through 9.5.6, and 9.6.x through 9.6.2. This issue stems from the improper enforcement of SSL/TLS connection requirements when the PGREQUIRESSL environment variable is set, creating a significant bypass mechanism that undermines the intended security controls. The flaw specifically targets the SSL connection handling logic within the PostgreSQL client-server communication framework, allowing attackers to circumvent mandatory encryption requirements that should otherwise protect data in transit.
The technical implementation of this vulnerability resides in the PostgreSQL connection management subsystem where the PGREQUIRESSL environment variable is designed to enforce SSL/TLS encryption for database connections. When this variable is properly configured, it should mandate that all client connections to the PostgreSQL server must utilize encrypted communication channels. However, the flaw allows attackers to strip the SSL/TLS protection from connections, effectively reverting to unencrypted communication channels despite the environment variable configuration. This represents a direct violation of the principle of least privilege and secure by default configurations that should govern database connectivity. The vulnerability manifests as a failure in the connection negotiation process where the system fails to properly validate and enforce the SSL requirement, creating a potential attack vector for man-in-the-middle operations.
The operational impact of CVE-2017-7485 is severe and multifaceted, particularly in environments where database traffic contains sensitive information such as personal data, financial records, or confidential business information. An active man-in-the-middle attacker positioned between a PostgreSQL client and server can exploit this vulnerability to downgrade connections from encrypted to unencrypted communication, potentially exposing sensitive data including authentication credentials, query results, and database schema information. This vulnerability directly violates the confidentiality and integrity requirements of the data protection framework, as defined by security standards such as the NIST Cybersecurity Framework and ISO 27001. The impact extends beyond simple data exposure to include potential authentication bypass scenarios and privilege escalation opportunities that could lead to complete database compromise.
The vulnerability aligns with CWE-310, which specifically addresses Cryptographic Issues, and represents a failure in cryptographic implementation where the system does not properly enforce cryptographic requirements. From an ATT&CK framework perspective, this vulnerability maps to T1046 Network Service Scanning and T1566 Impairing Defenses, as it allows attackers to manipulate network communications and weaken security controls. Organizations using affected PostgreSQL versions face significant risk of data breaches, compliance violations, and potential regulatory penalties under frameworks such as GDPR, HIPAA, and PCI DSS. The vulnerability also demonstrates poor input validation and configuration management practices that violate security best practices outlined in the OWASP Top Ten and the SANS Institute's Critical Security Controls.
The recommended mitigations for CVE-2017-7485 include immediate patching of affected PostgreSQL installations to the corrected versions 9.3.17, 9.4.12, 9.5.7, and 9.6.3 respectively, which contain the necessary fixes to properly enforce SSL/TLS requirements. Organizations should also implement additional network-level controls including firewall rules that restrict access to PostgreSQL ports, network segmentation to limit exposure, and monitoring systems that can detect anomalous connection patterns. The environment variable PGREQUIRESSL should be verified for proper configuration and implementation, with additional validation checks to ensure that SSL enforcement is consistently applied across all connection scenarios. Security teams should also implement comprehensive logging and audit procedures to monitor for potential exploitation attempts and establish incident response protocols specifically addressing SSL stripping attacks and connection downgrade scenarios.