CVE-2020-13692 in PostgreSQL
Summary
by MITRE
PostgreSQL JDBC Driver (aka PgJDBC) before 42.2.13 allows XXE.
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Analysis
by VulDB Data Team • 06/17/2025
The PostgreSQL JDBC Driver vulnerability identified as CVE-2020-13692 represents a critical security flaw that enables XML External Entity (XXE) processing within the database connectivity layer. This vulnerability affects versions prior to 42.2.13 of the PgJDBC driver, which is widely used by applications to establish connections between java applications and postgresql databases. The XXE vulnerability arises from improper handling of XML data structures within the driver's processing logic, creating a potential attack vector that could be exploited by malicious actors to manipulate the driver's behavior.
The technical implementation of this vulnerability stems from the driver's insufficient validation and sanitization of XML content when processing database responses or configuration data that may contain XML structures. When the JDBC driver encounters XML data that includes external entity references, it fails to properly restrict or disable external entity processing, allowing attackers to craft malicious XML payloads that can trigger unintended behavior. This flaw operates at the application layer and specifically impacts how the driver handles XML parsing operations during database communication. The vulnerability manifests when applications using the affected driver process XML responses from postgresql servers or when the driver itself processes XML configuration files that may contain external references.
The operational impact of CVE-2020-13692 extends beyond simple data manipulation and presents significant risks to database security and system integrity. Attackers could potentially leverage this vulnerability to perform server-side request forgery attacks, read arbitrary files from the server filesystem, or even execute remote code execution in certain configurations. The vulnerability's exploitation could lead to unauthorized access to sensitive database information, data exfiltration, and potential compromise of the entire database infrastructure. Organizations using the affected driver versions face increased risk of data breaches and system infiltration, particularly in environments where applications process untrusted XML data or where the driver handles database responses containing XML content.
Security mitigations for this vulnerability primarily involve immediate upgrade to PostgreSQL JDBC Driver version 42.2.13 or later, which includes proper XML entity handling and disables external entity processing by default. Organizations should also implement comprehensive network segmentation and access controls to limit exposure of systems using the vulnerable driver. Additional protective measures include disabling XML processing capabilities where possible, implementing strict input validation for all XML data, and conducting thorough security testing of applications that utilize the JDBC driver. This vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and maps to ATT&CK technique T1213.002 (Data from Information Repositories) and T1071.004 (Application Layer Protocol: DNS), emphasizing the need for robust XML security controls in database connectivity components.