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 Miosa-osa/OSA --skill offensive-open-redirectgit clone --depth 1 https://github.com/Miosa-osa/OSAWrote 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/miosa-osa/osa/offensive-open-redirect)<a href="https://agentmods.dev/skills/miosa-osa/osa/offensive-open-redirect"><img src="https://agentmods.dev/badge/skills/miosa-osa/osa/offensive-open-redirect/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/miosa-osa/osa/offensive-open-redirect"><img src="https://agentmods.dev/badge/skills/miosa-osa/osa/offensive-open-redirect.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 | $0.00055 | $0.04153 |
| Opus 5.5 | $0.00022 | $0.01661 |
| Sonnet 5.5 | $0.00011 | $0.00831 |
| Haiku 4.5 | $0.00006 | $0.00415 |
Grade A, and why
offensive-open-redirect scanned grade A with 1 finding 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
from urllib.parse import urlparse This is a copy
86% identical to offensive-open-redirect — 53 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.
How it starts
The opening of the file, as written. The whole thing — 519 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: Open Redirect Vulnerabilities
Metadata
- Skill Name: open-redirect
- Folder: offensive-open-redirect
- Source: https://github.com/SnailSploit/offensive-checklist/blob/main/open-redirect.md
Description
Open redirect vulnerability checklist: parameter identification, bypass techniques (URL encoding, double slashes, CRLF injection, protocol handlers), chaining with OAuth/SSRF, and impact escalation paths. Use for web app testing and bug bounty open redirect discovery.
Trigger Phrases
Use this skill when the conversation involves any of:
open redirect, URL redirect, redirect bypass, URL encoding bypass, CRLF, protocol handler, redirect chain, OAuth redirect, SSRF chain, open redirection
Full Methodology
Open Redirect Vulnerabilities
Shortcut
- Search for redirect URL parameters. These might be vulnerable to parameter based open redirect.
- Search for pages that perform referer based redirect. These are candidates for a referer based open redirect.
- Test the pages and parameters you've found for open redirect.
- If the server blocks the open redirect, try the protection bypass techniques mentioned before.
- Brainstorm ways of using the open redirect in your other bug chains.
Mechanisms
Open redirect vulnerabilities occur when web applications improperly validate user-supplied URLs used for redirections. These vulnerabilities allow attackers to craft links that appear legitimate but redirect victims to malicious websites. When exploited, the victim initially connects to a trusted domain, giving the malicious link an appearance of legitimacy, before being redirected to an attacker-controlled destination.
sequenceDiagram
participant Victim
participant TrustedSite
participant AttackerSite
Victim->>TrustedSite: Click malicious link<br/>trusted.com/redirect?url=evil.com
Note over TrustedSite: Inadequate URL validation
TrustedSite->>Victim: HTTP 302 Redirect to evil.com
Victim->>AttackerSite: Automatic redirect
AttackerSite->>Victim: Malicious content
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 · 519 lines · 55 tokens per session scan A 89b90f0ed95a
offensive-open-redirect is a skill published in the GitHub repository Miosa-osa/OSA (78 stars, last pushed 11d ago), licensed Apache-2.0. It adds 55 tokens to every session and 4,153 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). It is 86% identical to offensive-open-redirect, differing in 53 lines, and is treated as a copy.
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