CVE-2015-6938 in IPython Notebook
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the file browser in notebook/notebookapp.py in IPython Notebook before 3.2.2 and Jupyter Notebook 4.0.x before 4.0.5 allows remote attackers to inject arbitrary web script or HTML via a folder name. NOTE: this was originally reported as a cross-site request forgery (CSRF) vulnerability, but this may be inaccurate.
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Analysis
by VulDB Data Team • 06/18/2022
The CVE-2015-6938 vulnerability represents a critical cross-site scripting flaw that existed in the IPython Notebook application prior to version 3.2.2 and in Jupyter Notebook versions 4.0.x before 4.0.5. This vulnerability specifically affected the file browser component located in the notebook/notebookapp.py file, making it possible for remote attackers to execute malicious scripts within the context of other users' browsers. The flaw stemmed from inadequate input validation and output encoding mechanisms that failed to properly sanitize folder names before rendering them in the web interface, creating a persistent XSS vector that could be exploited across multiple versions of the popular data science and scientific computing platform.
The technical exploitation of this vulnerability occurred through the manipulation of folder names within the notebook's file browser interface. When users navigated to directories containing specially crafted malicious content in their names, the application would render this unescaped content directly into the HTML output without proper sanitization. This allowed attackers to inject arbitrary JavaScript code or HTML elements that would execute in the victim's browser context, potentially leading to session hijacking, data theft, or unauthorized actions performed on behalf of the authenticated user. The vulnerability was classified under CWE-79, which specifically addresses Cross-Site Scripting flaws in software applications, and aligns with ATT&CK technique T1566.001 for the initial access phase through malicious web content. The original classification as a CSRF vulnerability was later corrected, as the actual flaw was fundamentally an XSS issue rather than a request forgery problem, though both attack vectors could potentially be leveraged in combination within broader exploitation strategies.
The operational impact of CVE-2015-6938 was significant for organizations relying on IPython or Jupyter Notebook environments, particularly in research institutions, data science teams, and educational organizations where these platforms were commonly deployed. The vulnerability could be exploited by attackers who gained access to the file system or had the ability to create or modify folder names, potentially leading to unauthorized access to sensitive data, execution of malicious code on user systems, or manipulation of the notebook environment itself. In enterprise settings where multiple users shared notebook servers, this vulnerability created a persistent threat vector that could compromise entire user sessions and potentially lead to lateral movement within network environments. The impact extended beyond simple script execution to include potential privilege escalation scenarios where attackers could manipulate the notebook's operational context to perform unauthorized administrative actions.
Organizations should have immediately applied patches to upgrade to IPython Notebook 3.2.2 or Jupyter Notebook 4.0.5 to resolve the vulnerability. The mitigation strategy involved implementing proper input validation and output encoding mechanisms that would sanitize all user-provided folder names before rendering them in the browser interface. Security teams should have conducted comprehensive audits of their notebook environments to identify any potentially compromised systems and implemented additional monitoring for suspicious file operations. The vulnerability highlighted the importance of proper security practices in web applications, particularly around input sanitization and output encoding, and served as a reminder that even seemingly benign features like file browsing can become attack vectors when proper security controls are not implemented. Organizations should have also considered implementing web application firewalls and content security policies as additional protective measures to defend against similar vulnerabilities in their broader web application environments.