CVE-2024-11217 is a medium-severity vulnerability affecting OAuth-server versions 4.12.* through 4.18.*. The issue arises when the OAuth-server is configured with a log level set to Debug or higher, specifically during login flows involving OpenID Connect (OIDC) or identity providers such as GitHub, GitLab, and Google. Under these conditions, the OAuth2 client secret—a sensitive credential used to authenticate the client application to the authorization server—is logged in plaintext within debug messages. This exposure occurs because the server's logging mechanism does not adequately sanitize or redact sensitive information before writing to logs. Since client secrets are critical for maintaining the confidentiality and integrity of OAuth2 authentication flows, their disclosure can lead to unauthorized access if an attacker gains access to these logs. The vulnerability does not require user interaction and can be exploited remotely if an attacker has high-level privileges (as indicated by the CVSS vector requiring PR:H). The CVSS score of 4.9 reflects a medium severity, primarily due to the requirement for elevated privileges to access logs and the lack of direct impact on system availability or integrity. No known exploits are currently reported in the wild, and no patches or vendor advisories are linked yet. The vulnerability highlights a common security misconfiguration risk where verbose logging inadvertently leaks sensitive credentials, emphasizing the need for secure logging practices in identity and access management components.

For European organizations, this vulnerability poses a risk to the confidentiality of OAuth2 client secrets used in authentication systems integrating with popular identity providers like GitHub, GitLab, and Google. If an attacker with sufficient privileges accesses debug logs, they could retrieve client secrets and potentially impersonate legitimate clients, leading to unauthorized access to protected resources or services. This risk is particularly significant for enterprises relying on OAuth-server for single sign-on (SSO) or federated identity management, common in sectors such as finance, healthcare, and government. The exposure could facilitate lateral movement within networks or data breaches involving sensitive personal or corporate data, contravening GDPR requirements for data protection. However, the requirement for elevated privileges to access logs limits the attack surface, reducing the likelihood of widespread exploitation. Still, insider threats or compromised administrative accounts could leverage this vulnerability to escalate access. The absence of impact on integrity or availability means the threat is primarily confidentiality-focused but remains critical due to the sensitivity of the leaked secrets.

European organizations should immediately audit their OAuth-server logging configurations to ensure that log levels are not set to Debug or higher in production environments, especially where OAuth2 client secrets are involved. Implement log sanitization or redaction mechanisms to prevent sensitive information from being recorded. Access to logs must be strictly controlled with role-based access controls (RBAC) and monitored for unauthorized access attempts. Organizations should rotate OAuth2 client secrets if debug logs containing secrets have been exposed or accessed. Additionally, implement monitoring and alerting for anomalous authentication activities that could indicate misuse of compromised client secrets. Applying any available patches or updates from OAuth-server vendors as soon as they are released is critical. Finally, conduct regular security reviews of logging practices and integrate secure coding and configuration management policies to prevent similar issues in future deployments.