Security researchers have discovered a widespread path traversal vulnerability affecting 1,756 open-source projects on GitHub, with many carrying critical CVSS scores above 9.0.
The vulnerability stems from a seemingly innocuous code pattern that has been proliferating across the developer community for over a decade, creating cascading security risks throughout the software ecosystem.
Automated Detection Pipeline Reveals Scale of Problem
Researchers developed an automated pipeline to systematically identify and validate instances of the vulnerable code pattern at GitHub scale.
The pipeline encompasses detection through static analysis, exploitation verification, CVSS scoring, patch generation using GPT-4, and responsible disclosure to maintainers.
Starting with 40,546 candidate projects containing relevant keywords, the system filtered through multiple validation stages before confirming 1,756 exploitable instances.
The vulnerable pattern involves Node.js code that creates static HTTP file servers using a dangerous combination of URL pathname extraction and path joining operations.
Attackers can exploit this by providing malicious pathnames like “../../etc/passwd” to access files outside the intended public directory, compromising system confidentiality.
The vulnerability also enables denial-of-service attacks when requests target large files, potentially crashing server processes by exhausting available memory.
Despite comprehensive reporting efforts, the remediation rate remains concerningly low at just 14% among notified projects.
Researchers employed a staged disclosure approach, manually contacting popular projects with over 200 stars through private channels while submitting automated pull requests to smaller repositories.
Of 433 pull requests submitted, only 46 were accepted, with an additional 24 closed by maintainers.
Developer feedback revealed mixed responses to the vulnerability reports. Some maintainers dismissed the findings, claiming the code was only used for development or testing purposes, failing to recognize that such environments can still provide attack vectors.
Others questioned the legitimacy of the reports, viewing the large-scale notifications as potential spam.
LLM Contamination
The research traced the vulnerable code pattern’s origins to a 2010 GitHub Gist that garnered 543 stars and 204 forks.
Despite multiple developers raising security concerns over the years, the pattern migrated to prominent platforms including Mozilla developer documentation and StackOverflow, where it accumulated over 758,000 views on a single question page.
Perhaps most troubling, the study revealed that popular large language models have internalized this vulnerable pattern.
Testing across multiple LLM chatbots showed that 95% generated vulnerable code when prompted to create static file servers, and even when explicitly asked for secure implementations, 70% still produced exploitable code.
This contamination suggests the vulnerability will continue propagating as developers increasingly rely on AI-assisted coding tools.
The findings highlight the urgent need for improved security awareness in developer communities and more effective automated vulnerability management solutions to protect the open-source ecosystem from such widespread security flaws.
Find this Story Interesting! Follow us on LinkedIn and X to Get More Instant Updates.
