detecting-dependency-confusion

detecting-dependency-confusion is a skill for Claude Code, Codex from adriannoes/awesome-agentic-ai. It costs 24 tokens per session (2,734 once invoked), scanned A, original, MIT.

A security testing guide for detecting dependency confusion, an attack where a public package replaces a private company package with the same name in a build.

In plain words
What is it for?
Use it to review npm, PyPI, and Maven dependency resolution, test authorized build environments, and improve package-source controls.
Why use it?
It helps prevent build systems from downloading attacker-controlled code from public package registries.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to review npm, PyPI, and Maven dependency resolution, test authorized build environments, and improve package-source controls.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add adriannoes/awesome-agentic-ai --skill detecting-dependency-confusion
Clone the repo
git clone --depth 1 https://github.com/adriannoes/awesome-agentic-ai

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for detecting-dependency-confusion

README.md
[![agentmods](https://agentmods.dev/badge/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion/github.svg)](https://agentmods.dev/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion)
Your own site
<a href="https://agentmods.dev/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion"><img src="https://agentmods.dev/badge/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for detecting-dependency-confusion

Your own site · 80×15
<a href="https://agentmods.dev/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion"><img src="https://agentmods.dev/badge/skills/adriannoes/awesome-agentic-ai/detecting-dependency-confusion.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,734 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 5 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Privilege Escalation · line 31
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 53
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 135
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 220
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • medium MCP Rug Pull · line 51
    Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.
    Fix: Pin the image: image:tag or image@sha256:abc123
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00024 $0.02734
Opus 5 $0.00012 $0.01367
Sonnet 5 $0.00005 $0.00547
Haiku 4.5 $0.00002 $0.00273

Measured 7d ago against content hash ff2ca0885efe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

detecting-dependency-confusion scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/agent.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s -o /dev/null -w "%{http_code}\n" https://registry.npmjs.org/@acme%2finternal-utils
cursor-claude-codex/skills/anthropic-cybersecurity-skills/skills/detecting-dependency-confusion/SKILL.md · 225 lines

How it starts

The opening of the file, as written. The whole thing — 225 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Detecting Dependency Confusion

Legal Notice: This skill is for authorized security testing, defensive engineering, and educational purposes only. Registering or claiming package namespaces you do not own, or testing build pipelines without written authorization, may be illegal and may violate the terms of service of public registries. Only run namespace-claiming or resolution-testing activities against names and infrastructure you control or are explicitly authorized to assess.

Overview

Dependency confusion (also called a substitution or namespace-shadowing attack) was popularized by Alex Birsan in 2021 when he forced malicious code into the internal build systems of Apple, Microsoft, PayPal, and dozens of others. The root cause is that many package managers, when configured to resolve from both an internal/private registry and a public one, will prefer whichever copy has the higher version number rather than honoring the source. An attacker who learns the name of a private package (@acme/internal-utils, acme-billing-sdk) can publish a malicious package of the same name to the public registry (npmjs.com, PyPI, Maven Central) with a very high version (e.g. 99.0.0). When the victim's CI/CD runner or a developer machine resolves dependencies, it pulls the attacker's public package, executes its install scripts, and the supply chain is compromised.

This skill covers both halves of the problem: detection — enumerating internal package names that are not registered (squatted defensively) on public registries and are therefore claimable, using confused and OWASP dep-scan — and prevention — pinning scopes/namespaces to private registries, registering placeholder packages, and enforcing source restrictions in .npmrc, pip.conf/pyproject.toml, and Maven settings.xml. Internal package names leak constantly: in committed lockfiles, sourcemaps, public JS bundles, Docker layers, and error stack traces, so this is treated as an attack-surface management problem, not a one-time check.

Read the full file on GitHub · 225 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 225 lines · 24 tokens per session scan A ff2ca0885efe

Subscribe to this mod's changes

detecting-dependency-confusion is a skill published in the GitHub repository adriannoes/awesome-agentic-ai (57 stars, last pushed 13d ago), licensed MIT. It adds 24 tokens to every session and 2,734 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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