CVE-2025-21085 is a vulnerability identified in Ping Identity's PingFederate product, specifically affecting versions 11.3.0, 12.0, 12.1.0, and 12.2.0. The issue stems from a CWE-462 weakness, which involves the presence of duplicate keys in an associative list within the OAuth2 grant handling mechanism when using PostgreSQL as persistent storage. This flaw allows OAuth2 requests to trigger excessive memory utilization by duplicating OAuth2 grant entries in the database. The vulnerability is exploitable remotely over the network (AV:N) with low attack complexity (AC:L), but requires privileges (PR:L) and user interaction (UI:P). The impact primarily affects availability (VA:L), with no direct impact on confidentiality or integrity. The scope is partial (S:P), meaning the vulnerability affects components beyond the vulnerable component but within the same security scope. The vulnerability does not have known exploits in the wild as of the publication date (June 15, 2025). The CVSS 4.0 base score is 2.1, indicating a low severity level. The vulnerability could lead to denial-of-service conditions due to resource exhaustion, potentially degrading service performance or causing service outages in environments relying on PingFederate for OAuth2 authentication and authorization workflows. Since PingFederate is widely used for identity federation and single sign-on (SSO) in enterprise environments, improper handling of OAuth2 grants could impact authentication services, particularly in deployments using PostgreSQL for persistent storage of OAuth2 tokens and grants. The vulnerability requires some level of authentication and user interaction, which limits the ease of exploitation but still poses a risk in environments where attackers can interact with the OAuth2 endpoints under certain privileges.

For European organizations, the impact of CVE-2025-21085 could manifest as degraded availability of critical identity federation services, leading to potential disruptions in user authentication and authorization processes. Organizations relying on PingFederate for SSO and OAuth2 workflows may experience increased memory consumption on their PostgreSQL-backed systems, potentially causing service slowdowns or outages. This could affect business continuity, especially in sectors with high dependency on seamless authentication such as finance, healthcare, government, and telecommunications. While the vulnerability does not directly compromise confidentiality or integrity, denial-of-service conditions could indirectly affect operational security by forcing fallback to less secure authentication mechanisms or causing delays in access to critical systems. Additionally, the requirement for some privileges and user interaction means insider threats or compromised user accounts could be leveraged to exploit this vulnerability. European organizations with complex identity and access management (IAM) infrastructures that integrate PingFederate with PostgreSQL are particularly at risk. The absence of known exploits in the wild reduces immediate risk but should not lead to complacency given the potential for resource exhaustion attacks.

To mitigate CVE-2025-21085, European organizations should: 1) Prioritize upgrading PingFederate to a patched version once available from Ping Identity, as no patch links are currently provided but are expected given the publication status. 2) Implement strict access controls and monitoring on OAuth2 endpoints to detect abnormal usage patterns indicative of grant duplication attempts or excessive memory consumption. 3) Limit privileges required to interact with OAuth2 grant endpoints, ensuring only trusted and authenticated users can perform sensitive operations. 4) Monitor PostgreSQL database performance and resource utilization closely, setting alerts for unusual memory spikes that could indicate exploitation attempts. 5) Employ rate limiting and throttling on OAuth2 requests to reduce the risk of resource exhaustion. 6) Conduct regular audits of OAuth2 grant entries in PostgreSQL to identify and clean up duplicate or anomalous records. 7) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious OAuth2 grant manipulation patterns. 8) Educate administrators and users about the risk of social engineering or phishing that could lead to the required user interaction for exploitation. These measures, combined with timely patching, will reduce the likelihood and impact of exploitation.