Authentication bypass via disabled JWT signature verification
Published Feb 25, 2025 · Updated Feb 25, 2025
Improper JWT signature verification in JupyterHub LTI Authenticator 1.3.0 allows remote attackers to gain access via forged LTI requests. LTI13LaunchValidator.jwt_verify_and_decode retrieves a matching JWK but calls jwt.decode with signature verification disabled, accepting attacker-controlled claims. Exposure requires a JupyterHub deployment configured with LTI13Authenticator; a forged launch can gain access under existing or new user identities.
Summary
What happened
Improper JWT signature verification in JupyterHub LTI Authenticator 1.3.0 allows remote attackers to gain access via forged LTI requests. LTI13LaunchValidator.jwt_verify_and_decode retrieves a matching JWK but calls jwt.decode with signature verification disabled, accepting attacker-controlled claims. Exposure requires a JupyterHub deployment configured with LTI13Authenticator; a forged launch can gain access under existing or new user identities.
The record
- CVE
- CVE-2023-25574
- Published
- Feb 25, 2025
- Updated
- Feb 25, 2025
- Vendor
- JupyterHub
- Product
- LTI Authenticator
- Classifications
- CWE-347, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 25, 2025CVE publishedPublication date reported by the CVE source.
- Feb 25, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion== 1.3.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo