# Offensive Dependency Confusion

Deep-dive offensive methodology for dependency confusion and namespace attacks across...

- Repository: https://github.com/SnailSploit/Claude-Red (10186 stars)
- Category: Security
- License: MIT
- Last updated: 2026-10-12
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add SnailSploit/Claude-Red --skill offensive-dependency-confusion -g -a claude-code -y`
Codex: `npx skills add SnailSploit/Claude-Red --skill offensive-dependency-confusion -g -a codex -y`
Cursor: `npx skills add SnailSploit/Claude-Red --skill offensive-dependency-confusion -g -a cursor -y`
Gemini CLI: `npx skills add SnailSploit/Claude-Red --skill offensive-dependency-confusion -g -a gemini-cli -y`

## Description

Deep-dive offensive methodology for dependency confusion and namespace attacks across all major package ecosystems. Covers npm scope confusion exploiting the gap between public and private scoped packages and .npmrc misconfigurations where registry mappings fail to pin internal scopes exclusively. Addresses PyPI namespace attacks through --extra-index-url resolution ordering, NuGet feed priority exploitation when multiple package sources are configured without clear directives, Maven and Gradle repository ordering where artifact resolution traverses repositories sequentially, Go module proxy abuse through GOPROXY misconfiguration, Ruby gems namespace squatting, and Docker image tag confusion with unqualified image references. Provides complete proof-of-concept methodology using safe callbacks including DNS canary via interactsh or Burp Collaborator and HTTP beacon with no destructive payload. Covers reconnaissance techniques for discovering internal package names through GitHub repository analysis, error message harvesting, JavaScript source map extraction, lock file parsing, job postings mentioning internal tools, and package manifest inspection. Directly references and builds upon Alex Birsan's seminal 2021 dependency confusion research. Each ecosystem section includes registry-specific exploitation mechanics, configuration vulnerabilities, and defensive countermeasures for engagement reporting.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Offensive Dependency Confusion and Namespace Attacks

Dependency confusion exploits a fundamental design tension in package managers:
the need to resolve packages from multiple sources. When an organization
maintains internal packages alongside public dependencies, the resolution
logic becomes an attack surface. You exploit the gap between how developers
intend packages to resolve and how package managers actually resolve them.

Alex Birsan's 2021 research demonstrated that this class of attack affected
Apple, Microsoft, PayPal, Shopify, Netflix, Yelp, Tesla, and Uber, among
others. The root cause -- preferring a higher-versioned public package over
a lower-versioned private one -- remains exploitable wherever registry
configuration is incomplete.

This skill provides ecosystem-specific exploitation techniques, safe PoC
methodology, and comprehensive reconnaissance approaches for discovering
internal package names during authorized engagements.

## Quick Workflow

1. Perform reconnaissance to discover internal/private package names used by the target.
2. Identify the target's package ecosystems and registry configuration.
3. Verify that candidate package names are unclaimed on the corresponding public registry.
4. Prepare a safe PoC package with a DNS canary or HTTP callback and a high version number.
5. Publish the PoC to the public registry with a clear security research description.
6. Monitor the callback endpoint for execution confirmations from target infrastructure.
7. Record callback metadata (hostname, username, CI flag, timestamp) as evidence.
8. Remove the PoC package from the public registry after confirmation or engagement window closes.
9. Document the full attack chain, impacted systems, and registry hardening recommendations.

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## Reconnaissance for Internal Package Names

Discovering what internal packages a target uses is the critical first step.
You extract package names from every available artifact and signal.

### Lock File Analysis

The rest: https://github.com/SnailSploit/Claude-Red/blob/HEAD/Skills/supply-chain/offensive-dependency-confusion/SKILL.md