CVE-2025-30167: Jupyter Core Privilege Escalation Flaw

CVE-2025-30167 Overview

Jupyter Core, a foundational package providing core common functionality for Jupyter projects, contains an Uncontrolled Search Path Element vulnerability (CWE-427) in versions prior to 5.8.0 on Windows systems. The vulnerability stems from the application's use of the shared %PROGRAMDATA% directory for searching configuration files through SYSTEM_CONFIG_PATH and SYSTEM_JUPYTER_PATH. This design flaw allows unprivileged users on shared Windows systems to create malicious configuration files that affect other users, potentially leading to code execution or privilege escalation within the Jupyter environment.

Critical Impact
On shared Windows systems with multiple users and unprotected %PROGRAMDATA% directories, attackers with local access can plant malicious configuration files that execute in the context of other users running Jupyter applications.

Affected Products

Jupyter Core versions prior to 5.8.0
Windows systems with shared %PROGRAMDATA% directories
Multi-user Windows environments with default directory permissions

Discovery Timeline

2025-06-03 - CVE CVE-2025-30167 published to NVD
2025-09-08 - Last updated in NVD database

Technical Details for CVE-2025-30167

Vulnerability Analysis

This vulnerability falls under CWE-427 (Uncontrolled Search Path Element), a class of weaknesses where an application searches for critical resources using an externally-supplied search path that can point to resources outside the intended control sphere.

In the case of Jupyter Core on Windows, the application searches for configuration files in the %PROGRAMDATA% directory, which is a shared system location. By default, this directory may have overly permissive access controls that allow standard users to create files and subdirectories. When Jupyter Core loads configuration files from this location, it trusts the content without adequate verification of the file's origin or integrity.

The attack requires local access to the system and depends on the target environment having multiple users with unprotected %PROGRAMDATA% directory permissions. When these conditions are met, an attacker can create a %PROGRAMDATA%\jupyter directory structure containing malicious configuration files that will be loaded by other users when they run Jupyter applications.

Root Cause

The root cause lies in Jupyter Core's configuration file search path implementation on Windows systems. The application includes %PROGRAMDATA% as part of SYSTEM_CONFIG_PATH and SYSTEM_JUPYTER_PATH without adequately verifying the permissions or ownership of the directory. This allows any local user who can write to %PROGRAMDATA% to influence the configuration of Jupyter applications for all users on the system.

The fundamental issue is a failure to apply the principle of least privilege when determining trusted configuration file locations. On multi-user systems, shared directories should either be excluded from the search path or the application should validate that configuration files in these locations are only writable by administrators.

Attack Vector

The attack vector is local, requiring the attacker to have user-level access to a shared Windows system. The attack proceeds as follows:

The attacker identifies a Windows system with Jupyter Core installed where multiple users share the system
The attacker checks that %PROGRAMDATA% is writable (default on many Windows configurations)
The attacker creates the %PROGRAMDATA%\jupyter directory if it doesn't exist
The attacker places malicious configuration files in this directory
When another user launches a Jupyter application, the malicious configuration is loaded and executed in their security context

The vulnerability requires user interaction (the victim must launch a Jupyter application) but has the potential for high impact on confidentiality, integrity, and availability of the victim's session and data.

Detection Methods for CVE-2025-30167

Indicators of Compromise

Unexpected files or directories created under %PROGRAMDATA%\jupyter by non-administrator users
Configuration files in %PROGRAMDATA%\jupyter with suspicious content or recent modification times
Unusual process behavior or network connections originating from Jupyter processes
File system audit logs showing creation of jupyter configuration files by unprivileged accounts

Detection Strategies

Monitor file system changes to %PROGRAMDATA%\jupyter and alert on creations by non-administrator accounts
Implement file integrity monitoring for Jupyter configuration directories across all search paths
Review Jupyter configuration file contents for suspicious entries such as startup scripts or extension configurations
Use endpoint detection and response (EDR) solutions to monitor process chains originating from Jupyter applications

Monitoring Recommendations

Enable Windows Security Auditing for Object Access on the %PROGRAMDATA% directory
Deploy SentinelOne agents to monitor for suspicious file system modifications in shared configuration directories
Implement application whitelisting to control what executables can be launched by Jupyter processes
Review user access patterns on shared systems to identify potential exploitation attempts

How to Mitigate CVE-2025-30167

Immediate Actions Required

Upgrade Jupyter Core to version 5.8.0 or later immediately on all affected systems
Audit %PROGRAMDATA%\jupyter directories for any unauthorized configuration files
Review permissions on %PROGRAMDATA% to ensure only administrators have write access
Implement monitoring for file system changes in shared configuration directories

Patch Information

Users should upgrade to Jupyter Core version 5.8.0 or later to receive the security patch. The fix addresses the configuration file search path handling on Windows systems. For detailed information about the vulnerability and patch, refer to the GitHub Security Advisory GHSA-33p9-3p43-82vq.

The patch can be applied by upgrading through pip:

bash

pip install --upgrade jupyter_core>=5.8.0

Workarounds

As administrator, modify permissions on the %PROGRAMDATA% directory to prevent unauthorized users from writing files
As administrator, proactively create the %PROGRAMDATA%\jupyter directory with restrictive permissions (administrator-only write access)
As user or administrator, set the %PROGRAMDATA% environment variable to point to a directory with appropriately restrictive permissions controlled by administrators or the current user
Consider running Jupyter in isolated user environments or containers to limit the impact of configuration hijacking