Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/JustineDevs/premortemnpx agentmods add skills/justinedevs/premortem/waf-bypass-techniquesWrote 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/justinedevs/premortem/waf-bypass-techniques)<a href="https://agentmods.dev/skills/justinedevs/premortem/waf-bypass-techniques"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/waf-bypass-techniques/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/justinedevs/premortem/waf-bypass-techniques"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/waf-bypass-techniques.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 | $0.00057 | $0.03074 |
| Opus 5 | $0.00028 | $0.01537 |
| Sonnet 5 | $0.00011 | $0.00615 |
| Haiku 4.5 | $0.00006 | $0.00307 |
Grade A, and why
waf-bypass-techniques 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 6d 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.
This is a copy
94% identical to waf-bypass-techniques — 8 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 — 291 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SKILL: WAF Bypass Techniques — Evasion Playbook
AI LOAD INSTRUCTION: Covers WAF identification, generic bypass categories (encoding, protocol abuse, HTTP/2, parameter pollution), and a decision tree. For product-specific bypasses (CDN, AWS WAF, ModSecurity, Akamai, etc.), load WAF_PRODUCT_MATRIX.md. Base models often suggest basic encoding but miss protocol-level bypasses and WAF behavioral quirks.
0. RELATED ROUTING
- sqli-sql-injection for payloads to deliver after bypassing WAF
- xss-cross-site-scripting for XSS payloads that need WAF evasion
- request-smuggling when smuggling can route requests around WAF entirely
- http-parameter-pollution HPP is itself a WAF bypass primitive
- csp-bypass-advanced when WAF blocks inline scripts but CSP bypass is available
- ghost-bits-cast-attack Java backends only — when every encoding trick above is blocked, use Ghost Bits: Java's 16-bit
charto 8-bitbytenarrowing produces 255 Unicode bypass variants per dangerous ASCII byte; re-enables WAF-patched CVEs in Tomcat, Spring, Jetty, Jackson, Fastjson, BCEL, and more
Product-Specific Reference
Load WAF_PRODUCT_MATRIX.md when you need per-product bypass techniques for CDN, AWS WAF, ModSecurity CRS, Akamai, Imperva, F5 BIG-IP, or Sucuri.
1. PHASE 0 — IDENTIFY THE WAF
Before bypassing, know what you're fighting.
1.1 Tools
| Tool | Usage |
|---|---|
wafw00f target.com |
Fingerprint WAF vendor from response headers/behavior |
nmap --script=http-waf-detect |
NSE script for WAF detection |
| Manual header inspection | Server, X-CDN, X-Cache, cf-ray (CDN), x-sucuri-id, x-akamai-* |
1.2 Behavioral Fingerprinting
1. Send benign request → record baseline response (status, headers, body size)
2. Send obvious attack: /?q=<script>alert(1)</script>
3. Compare: 403? Custom block page? Redirect? Connection reset?
4. Block page content reveals WAF: "CDN", "Access Denied (Imperva)", "ModSecurity"
5. If transparent proxy: check response time difference (WAF adds latency)
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 6d ago First seen · 291 lines · 57 tokens per session scan A edf5f0167a8a
waf-bypass-techniques is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 57 tokens to every session and 3,074 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 94% identical to waf-bypass-techniques, differing in 8 lines, and is treated as a copy.
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