hunting-mass-assignment-and-property-authz SKILL.md skillA
hunting-mass-assignment-and-property-authz from unboundcompute/security-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add unboundcompute/security-agent-skills/hunting-mass-assignment-and-property-authz@git:20260819.0218064Pins git:20260819.0218064 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- unboundcompute/security-agent-skills
- Path
skills/hunting-mass-assignment-and-property-authz/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260819.0218064, committed Aug 19, 2026
- Size
- 8,770 bytes
- Repository stars
- 26
- License
- MIT
Hunt mass assignment and broken object-property authorization: handlers that bind a client request payload straight onto a record or model and let the caller write fields it should never control - role, is_admin, owner_id, tenant, price, balance, verified, status, or another user's foreign key. Covers auto-binding and hydration that take the whole payload, blocklist filters that miss a field, nested and relation fields that reopen the hole, type juggling that flips a flag, and read paths that…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Hunting mass assignment: which fields, not which object Broken object-level authorization asks whether the caller may reach *this object*. Mass assignment asks the next question: given an object the caller may write, which of its *fields* may they set? The bug is a handler that binds a request payload onto a record and trusts the client to send only the fields it should, so an attacker adds `"role":"admin"`, `"owner_id": <someone else>`, `"price": 0`, or `"verified": true` to a payload the endpoint was never meant to accept, and the framework writes it. You find it by listing what the client can put into the payload, following it to the record write, and asking which of those fields the server, not the client, is supposed to own. ## When to use - You are reviewing a create or update handler that maps request fields onto a persisted object. - The framework auto-binds or hydrates a payload onto a model, struct, or record. - Some properties of the object are meant to be server-controlled: privilege, ownership, tenancy, money, state, or verification flags. ## Scope check Test property writes only in systems you own or are authorized to test, with accounts …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/hunting-mass-assignment-and-property-authz@sha256:475f5a95f8e7bd97The line at the top of this page pins the label git:20260819.0218064, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_gbuzzi273ieoet37)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Aug 19, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (8770 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
unboundcompute/security-agent-skills · 26 stars · license MIT · pushed 2026-09-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_gbuzzi273ieoet37 GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/hunting-mass-assignment-and-property-authz GET https://markdownregistry.com/api/v1/blob/475f5a95f8e7bd97084708d5738406a9805806aae6475a076aebb223c2f42ea2
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.