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.
npx skills add UnboundCompute/security-agent-skills --skill hunting-dns-rebinding-and-ssrf-pivotsgit clone --depth 1 https://github.com/UnboundCompute/security-agent-skillsWrote 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.
[](https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-dns-rebinding-and-ssrf-pivots)<a href="https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-dns-rebinding-and-ssrf-pivots"><img src="https://agentmods.dev/badge/skills/unboundcompute/security-agent-skills/hunting-dns-rebinding-and-ssrf-pivots/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.
<a href="https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-dns-rebinding-and-ssrf-pivots"><img src="https://agentmods.dev/badge/skills/unboundcompute/security-agent-skills/hunting-dns-rebinding-and-ssrf-pivots.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00189 | $0.02114 |
| Opus 5.5 | $0.00076 | $0.00846 |
| Sonnet 5.5 | $0.00038 | $0.00423 |
| Haiku 4.5 | $0.00019 | $0.00211 |
Grade A, and why
hunting-dns-rebinding-and-ssrf-pivots 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hunting DNS rebinding and SSRF pivots: turning the server into a proxy for the inside
Server-side request forgery is a position bug: a server sits inside the network with a fetcher that will connect to a destination the caller influences, and internal services around it trust callers by where they come from rather than who they are. So if an attacker can steer the server's outbound request, the server becomes their proxy into internal space, the cloud metadata endpoint, an admin port, a database that assumes anyone who can reach it belongs. DNS rebinding is the technique that defeats the usual defense: the server validates the hostname, sees a public address, and allows it, but between that check and the actual connection the attacker's DNS answer changes to an internal address, so the connection lands somewhere the check never approved. The same slip happens through a redirect the fetcher follows. The hunt is for caller-influenced destinations and for the gap between validating and connecting. You hunt this by finding server fetchers and testing whether the destination they connect to can be moved after the check.
When to use
- A server fetches, imports, previews, or calls out to a URL or hostname a caller can influence.
- Validation of the destination may happen at check time while the connection resolves the name again later.
- Internal services (metadata endpoint, admin ports, datastores) trust callers by network position.
Scope check
Test SSRF and rebinding only against systems you own or are authorized to assess, on non-production endpoints. A confirmed pivot reaches real internal services and credentials, so stop at proof of reach, do not read or exfiltrate internal data, and use benign markers. If you can't name the authorization, stop.
The loop
- Establish the fetcher's intended destinations first. Name where each server-side fetch is legitimately supposed to go: a specific allowed host, a public API, never internal space. This is the false-positive killer: a fetcher restricted to an allowlist that is re-checked at connect time, with internal services that authenticate rather than trust position, cannot be pivoted. Name the intended destinations, then find where the caller can influence them.
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.
- 1mo ago First seen · 140 lines · 189 tokens per session scan A b931a3d5099a
hunting-dns-rebinding-and-ssrf-pivots is a skill published in the GitHub repository UnboundCompute/security-agent-skills (5 stars, last pushed 1mo ago), licensed MIT. It adds 189 tokens to every session and 2,114 once invoked, about $0.0008 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.
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