hunting-crlf-and-response-splitting SKILL.md skillA
hunting-crlf-and-response-splitting from unboundcompute/security-agent-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add unboundcompute/security-agent-skills/hunting-crlf-and-response-splitting@git:20260903.6dac719Pins git:20260903.6dac719 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- unboundcompute/security-agent-skills
- Path
skills/hunting-crlf-and-response-splitting/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260903.6dac719, committed Sep 3, 2026
- Size
- 9,819 bytes
- Repository stars
- 26
- License
- MIT
Hunt CRLF injection where untrusted input carrying a carriage return and line feed reaches a response header, a log line, or an outbound email header that does not strip or reject those characters, letting the attacker inject headers, split the message, forge log entries, or add email headers. Use when input flows into a Set-Cookie, Location, or custom response header, into a log written from request data, or into mail headers built from user input. Covers full response splitting into injected…
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
# Hunting CRLF and response splitting: when a newline becomes a new header Headers, log lines, and email headers are all line-oriented: a carriage return and line feed ends one field and begins the next. When untrusted input flows into one of these unescaped, an attacker who supplies a CRLF sequence stops writing a value and starts writing structure. A newline in a redirect location injects a header, or a blank line followed by a body splits the response into a second one the attacker controls. A newline in a log line forges an entry that frames another user or hides an action. A newline in a mail header adds recipients or spoofs fields. The bug is not the input; it is a writer that concatenates untrusted text into a line-structured format without rejecting the line terminators. You find these by locating every header, log, and email write fed request data and checking whether CR and LF survive. ## When to use - Request input flows into a response header value: a Set-Cookie, a Location redirect, or a custom header. - Log lines are written from request data (paths, user agents, identifiers) without neutralizing newlines. …
Read the whole file at its exact version.
How to install
mdr add unboundcompute/security-agent-skills/hunting-crlf-and-response-splitting@sha256:76d4ad59e2b3a257The line at the top of this page pins the label git:20260903.6dac719, 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_cwgecz633e4edqwp)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Sep 3, 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 (9819 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
unboundcompute/security-agent-skills · 26 stars · license MIT · pushed 2026-09-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_cwgecz633e4edqwp GET https://markdownregistry.com/api/v1/resolve?ref=unboundcompute/security-agent-skills/hunting-crlf-and-response-splitting GET https://markdownregistry.com/api/v1/blob/76d4ad59e2b3a25775540ac3fe1ec252a081fb633729baaece7e273b2a0f85a1
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.