CVE-2023-25574 in ltiauthenticator
Summary
by MITRE • 02/25/2025
`jupyterhub-ltiauthenticator` is a JupyterHub authenticator for learning tools interoperability (LTI). LTI13Authenticator that was introduced in `jupyterhub-ltiauthenticator` 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request. Only users that has configured a JupyterHub installation to use the authenticator class `LTI13Authenticator` are affected. `jupyterhub-ltiauthenticator` version 1.4.0 removes LTI13Authenticator to address the issue. No known workarounds are available.
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Analysis
by VulDB Data Team • 09/03/2025
The CVE-2023-25574 vulnerability affects the jupyterhub-ltiauthenticator package, specifically targeting the LTI13Authenticator component introduced in version 1.3.0. This authenticator implements the Learning Tools Interoperability 1.3 standard which enables secure communication between learning management systems and external tools. The vulnerability stems from a critical flaw in the JWT signature validation process, where the authenticator fails to properly verify the cryptographic signatures of incoming authentication requests. This represents a fundamental breakdown in the security model of the authentication mechanism, as it allows malicious actors to forge authentication tokens that would otherwise be rejected by proper signature validation.
The technical flaw manifests as a missing cryptographic validation step within the LTI13Authenticator implementation, directly correlating to CWE-347 - Improper Verification of Cryptographic Signature. When a user configures a JupyterHub installation to utilize the LTI13Authenticator class, the system accepts potentially malicious requests that contain forged JWT tokens without proper signature verification. This vulnerability creates an authentication bypass scenario where unauthorized users can gain access to the JupyterHub environment through manipulated LTI authentication flows. The absence of any known workarounds means that affected installations cannot implement temporary mitigations while awaiting the official fix.
The operational impact of this vulnerability is significant for organizations running JupyterHub instances that have integrated LTI13Authenticator for educational or research purposes. Attackers exploiting this vulnerability could gain unauthorized access to computational resources, potentially leading to data breaches, code execution, or disruption of educational services. The vulnerability affects the core authentication mechanism, making it a critical security concern for any deployment where user access control is paramount. The remediation strategy involves upgrading to version 1.4.0 of jupyterhub-ltiauthenticator which completely removes the vulnerable LTI13Authenticator component, following ATT&CK technique T1566.002 - Phishing: Spearphishing Attachment for the initial compromise vector and T1078 - Valid Accounts for maintaining access once the vulnerability is exploited. Organizations should also conduct thorough security audits of their JupyterHub configurations and implement proper monitoring for unauthorized authentication attempts.
The vulnerability demonstrates a failure in the security testing and code review processes for authentication components, particularly in the area of cryptographic implementation. The LTI13 standard itself is designed to provide secure single sign-on capabilities, but this implementation flaw undermines the entire security framework. This type of vulnerability is particularly dangerous in educational environments where JupyterHub instances may contain sensitive research data, student information, or proprietary code. The security implications extend beyond simple unauthorized access to include potential privilege escalation and lateral movement within the affected systems. The vulnerability classification aligns with security frameworks emphasizing the importance of proper cryptographic implementation and validation in authentication systems, particularly those handling sensitive educational data in cloud-based environments.