saml-sso-assertion-attacks

saml-sso-assertion-attacks is a skill for Claude Code, Codex from miru-zero/zero-brain. It costs 44 tokens per session (489 once invoked), scanned A, a copy of saml-sso-assertion-attacks, MIT.

A guide to testing SAML-based single sign-on, a login system where an identity provider sends XML statements about a user to an application. It focuses on whether those statements and their source are properly checked.

In plain words
What is it for?
It helps test signatures, issuer and audience checks, login endpoints, replay protection, account mapping, and XML parsing.
Why use it?
It helps find login flaws caused by accepting forged, altered, replayed, or incorrectly targeted SAML statements.

Skill for Claude CodeCodex

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

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.

agentmods
npx agentmods add skills/miru-zero/zero-brain/saml-sso-assertion-attacks
Any agent
npx skills add miru-zero/zero-brain --skill saml-sso-assertion-attacks
Clone the repo
git clone --depth 1 https://github.com/miru-zero/zero-brain

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 saml-sso-assertion-attacks

README.md
[![agentmods](https://agentmods.dev/badge/skills/miru-zero/zero-brain/saml-sso-assertion-attacks.svg)](https://agentmods.dev/skills/miru-zero/zero-brain/saml-sso-assertion-attacks)
Your own site
<a href="https://agentmods.dev/skills/miru-zero/zero-brain/saml-sso-assertion-attacks"><img src="https://agentmods.dev/badge/skills/miru-zero/zero-brain/saml-sso-assertion-attacks.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 489 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 95% copy Near-identical to another mod 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 $0.00044 $0.00489
Opus 5 $0.00022 $0.00244
Sonnet 5 $0.00009 $0.00098
Haiku 4.5 $0.00004 $0.00049

Measured 2d ago against content hash 1424245d3409, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

saml-sso-assertion-attacks scanned grade A with 0 findings 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 2d ago.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

95% identical to saml-sso-assertion-attacks — 4 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/saml-sso-assertion-attacks/SKILL.md · 41 lines

What it actually says

SKILL: SAML SSO and Assertion Attacks — Signature Validation, Binding, and Trust Confusion

AI LOAD INSTRUCTION: Use this skill when the target uses SAML-based SSO and you need to validate assertion trust: signature coverage, audience and recipient checks, ACS handling, XML parsing weaknesses, and IdP/SP confusion.

1. WHEN TO LOAD THIS SKILL

Load when:

  • Enterprise SSO uses SAML requests or responses
  • You see SAMLRequest, SAMLResponse, XML assertions, or ACS endpoints
  • Login flows involve an external IdP and browser POST/redirect binding

2. HIGH-VALUE MISCONFIGURATION CHECKS

Theme What to Check
signature validation unsigned assertion accepted, wrong node signed, signature wrapping
audience and recipient weak Audience, Recipient, Destination, or ACS validation
issuer trust wrong IdP accepted or multi-tenant issuer confusion
replay and freshness missing InResponseTo, weak NotBefore / NotOnOrAfter enforcement
account mapping email-only binding, case folding, unverified attributes
XML parser behavior XXE-like parser issues or unsafe transforms around SAML documents

3. QUICK TRIAGE

  1. Capture one full login round trip.
  2. Inspect which XML nodes are signed and which attributes drive account binding.
  3. Compare SP-initiated and IdP-initiated flows.
  4. Test replay, altered attributes, and assertion placement confusion.
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. 2d ago First seen · 41 lines · 44 tokens per session scan A 1424245d3409

Subscribe to this mod's changes

saml-sso-assertion-attacks is a skill published in the GitHub repository miru-zero/zero-brain (0 stars, last pushed 18d ago), licensed MIT. It adds 44 tokens to every session and 489 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to saml-sso-assertion-attacks, differing in 4 lines, and is treated as a copy.

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