ctf-pwn

ctf-pwn is a skill for Claude Code from cyberkaida/reverse-engineering-assistant. It costs 46 tokens per session (5,098 once invoked), scanned A, original, Apache-2.0.

A guide to solving capture-the-flag challenges that contain software bugs allowing data to be written into unintended parts of a program's memory.

In plain words
What is it for?
Use it for binary exploitation tasks involving buffer overflows, format strings, heap errors, or return-oriented programming.
Why use it?
It gives a structured way to trace attacker-controlled input, understand memory corruption, and turn the bug into access to the challenge's flag.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the ReVa plugin — 6 skills, 1 MCP server shipped together

Good fit Use it for binary exploitation tasks involving buffer overflows, format strings, heap errors, or return-oriented programming.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cyberkaida/reverse-engineering-assistant/ctf-pwn
Install

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.

Any agent
npx skills add cyberkaida/reverse-engineering-assistant --skill ctf-pwn
Clone the repo
git clone --depth 1 https://github.com/cyberkaida/reverse-engineering-assistant

Made for: Claude Code.

Or install ReVa, the plugin that ships this one along with the rest of its 6 skills, 1 MCP server.

Wrote 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.

agentmods badge for ctf-pwn

README.md
[![agentmods](https://agentmods.dev/badge/skills/cyberkaida/reverse-engineering-assistant/ctf-pwn.svg)](https://agentmods.dev/skills/cyberkaida/reverse-engineering-assistant/ctf-pwn)
Your own site
<a href="https://agentmods.dev/skills/cyberkaida/reverse-engineering-assistant/ctf-pwn"><img src="https://agentmods.dev/badge/skills/cyberkaida/reverse-engineering-assistant/ctf-pwn.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,098 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00046 $0.05098
Opus 5 $0.00023 $0.02549
Sonnet 5 $0.00009 $0.01020
Haiku 4.5 $0.00005 $0.00510

Measured 8d ago against content hash c7a76697602d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ctf-pwn 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 8d 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.

ReVa/skills/ctf-pwn/SKILL.md · 533 lines

How it starts

The opening of the file, as written. The whole thing — 533 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CTF Binary Exploitation (Pwn)

Purpose

You are a CTF binary exploitation specialist. Your goal is to discover memory corruption vulnerabilities and exploit them to read flags through systematic vulnerability analysis and creative exploitation thinking.

This is a generic exploitation framework - adapt these concepts to any vulnerability type you encounter. Focus on understanding why memory corruption happens and how to manipulate it, not just recognizing specific bug classes.

Conceptual Framework

The Exploitation Mindset

Think in three layers:

  1. Data Flow Layer: Where does attacker-controlled data go?

    • Input sources: stdin, network, files, environment, arguments
    • Data destinations: stack buffers, heap allocations, global variables
    • Transformations: parsing, copying, formatting, decoding
  2. Memory Safety Layer: What assumptions does the program make?

    • Buffer boundaries: Fixed-size arrays, allocation sizes
    • Type safety: Integer types, pointer validity, structure layouts
    • Control flow integrity: Return addresses, function pointers, vtables
  3. Exploitation Layer: How can we violate trust boundaries?

    • Memory writes: Overwrite critical data (return addresses, function pointers, flags)
    • Memory reads: Leak information (addresses, canaries, pointer values)
    • Control flow hijacking: Redirect execution to attacker-controlled locations
    • Logic manipulation: Change program state to skip checks or trigger unintended paths

Core Question Sequence

For every CTF pwn challenge, ask these questions in order:

  1. What data do I control?

    • Function parameters, user input, file contents, environment variables
    • How much data? What format? Any restrictions (printable chars, null bytes)?
  2. Where does my data go in memory?

    • Stack buffers? Heap allocations? Global variables?
    • What's the size of the destination? Is it checked?
  3. What interesting data is nearby in memory?

    • Return addresses (stack)
    • Function pointers (heap, GOT/PLT, vtables)
    • Security flags or permission variables
    • Other buffers (to leak or corrupt)

Read the full file on GitHub · 533 lines

Files

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.

Changes

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.

  1. 8d ago First seen · 533 lines · 46 tokens per session scan A c7a76697602d

Subscribe to this mod's changes

ctf-pwn is a skill published in the GitHub repository cyberkaida/reverse-engineering-assistant (823 stars, last pushed 4d ago), licensed Apache-2.0. It adds 46 tokens to every session and 5,098 once invoked, about $0.0002 per session on Opus 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 2026-08-30.

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