CVE-2019-9880 in WPGraphQL Plugin
Summary
by MITRE
An issue was discovered in the WPGraphQL 0.2.3 plugin for WordPress. By querying the 'users' RootQuery, it is possible, for an unauthenticated attacker, to retrieve all WordPress users details such as email address, role, and username.
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Analysis
by VulDB Data Team • 09/25/2025
The vulnerability identified as CVE-2019-9880 resides within the WPGraphQL plugin version 0.2.3 for WordPress, representing a critical information disclosure flaw that fundamentally undermines the security posture of affected systems. This vulnerability manifests through the GraphQL API endpoint that handles user data retrieval, specifically targeting the 'users' RootQuery functionality. The flaw enables unauthenticated attackers to systematically enumerate user accounts and extract sensitive information including usernames, email addresses, and role assignments without requiring any valid credentials or authentication tokens.
From a technical perspective, the vulnerability stems from inadequate access control mechanisms within the GraphQL query execution layer of the WPGraphQL plugin. The RootQuery interface for users lacks proper authentication checks, allowing any external party to submit GraphQL queries that traverse the user data structure and return comprehensive user profiles. This represents a direct violation of the principle of least privilege and demonstrates a classic authorization bypass vulnerability. The flaw operates at the application layer and is classified as a CWE-284 Access Control flaw, specifically manifesting as insufficient authorization checks for API endpoints. The vulnerability is particularly dangerous because it operates silently without generating detectable audit logs, making it difficult for administrators to identify unauthorized access attempts.
The operational impact of this vulnerability extends far beyond simple information disclosure, creating cascades of potential security risks for WordPress installations. Attackers can leverage this vulnerability to build comprehensive user directories that facilitate targeted social engineering attacks, credential stuffing campaigns, and privilege escalation attempts. The exposure of user email addresses and roles provides adversaries with valuable intelligence for spear-phishing operations and helps them understand the organizational structure of WordPress sites. Additionally, the vulnerability enables attackers to identify high-privilege users through role information, allowing them to prioritize their attack vectors against administrators or editors. This reconnaissance capability aligns with ATT&CK technique T1087.001 Account Discovery and represents a significant threat to the overall security of WordPress environments.
Mitigation strategies for CVE-2019-9880 should prioritize immediate plugin updates to versions that address the authentication bypass issue, as the vulnerability was resolved in subsequent releases of the WPGraphQL plugin. Organizations should also implement network-level restrictions to limit access to GraphQL endpoints, particularly when these endpoints are exposed to untrusted networks. The implementation of proper authentication mechanisms for GraphQL queries, including token-based authentication or API key management, provides additional layers of protection. Security monitoring should include detection of unusual GraphQL query patterns and unauthorized access attempts to user data endpoints. Administrators should also consider implementing web application firewalls that can filter malicious GraphQL queries and restrict access based on IP addresses or user agents. The vulnerability serves as a reminder of the critical importance of proper access control implementation in modern web applications, particularly in API-driven architectures where the exposure of user data can have severe consequences for organizational security.