phabricator-client 99.0.1

Security Research - Dependency Confusion PoC

phabricator-client — Security Research / Dependency Confusion PoC

Version 99.0.0

This package is published for security research purposes only as a proof-of-concept for a Dependency Confusion / Supply Chain vulnerability.

The package name was found unclaimed on the Python Package Index (PyPI) as an internal/workspace-only package that was never published publicly. This is a classic dependency confusion scenario where an attacker can register the missing package name and achieve code execution on any system that depends on it.

Why Dependency Confusion Works

When projects declare dependencies in pyproject.toml, setup.py, or requirements.txt, package managers like pip resolve the package name against the public registry (PyPI). If a package name is:

1. Declared as a dependency in a public repository
2. Referenced as a workspace/internal member but never published
3. Not pinned to a specific version or registry

→ Any attacker can register the missing name on PyPI and have their code executed by anyone installing the parent project.

The [tool.uv.sources] or workspace-only configuration only protects uv users within the monorepo. Standard tools like pip, poetry, and pipenv ignore these directives and resolve from PyPI — where the package did not exist until now.

Impact

Capability	Severity
Remote Code Execution during pip install	CRITICAL
Supply chain contamination of CI/CD pipelines	CRITICAL
Credential / token theft from build environments	CRITICAL
Persistent access as the dependency owner	HIGH

Remediation

• Publish the legitimate package to PyPI under an organization account
• Pin dependencies with version constraints
• Use a private/scoped package registry for internal packages
• Implement automated dependency confusion scanning in CI/CD

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This is a benign proof-of-concept. No malicious code is included.