Format String Exploitation

Format String Exploitation is a Quality skill for Claude Code, published by xalgord in xalgorix.

852 stars153 forkson xalgord/xalgorixAdded 2026/08/12+1% in starsRepository updated 2026/08/11

ai-agentai-securityautomationautonomous-pentestingbug-bountycybersecurityethical-hackinggolangpenetration-testingpentestpentesting-toolsreconsecuritysecurity-researchsecurity-toolstypescriptvulnerability-detectionvulnerability-scanner

Install in seconds

Install Format String Exploitation

Copy Format String Exploitation into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.

terminal

npx degit https://github.com/xalgorix/xalgorix/tree/main/internal/tools/skills/data/binary-exploitation/exploiting-format-string-vulnerabilities ~/.claude/skills/exploiting-format-string-vulnerabilities

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/xalgorix/xalgorix.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file: internal/tools/skills/data/binary-exploitation/exploiting-format-string-vulnerabilities/SKILL.md in xalgord/xalgorix
Installs to: ~/.claude/skills/exploiting-format-string-vulnerabilities
Collection: One of 51 skills cataloged from this repository
Category: Quality — 1354 skills

What Format String Exploitation does

Format String Exploitation outlines how to confirm, leak from, and write through format string bugs in authorized assessments. It covers finding the argument offset, leaking pointers or canaries, and using %n or %hn when available.

Format String Exploitation is cataloged under Quality on DirSkills. Format String Exploitation comes from a repository tagged ai-agent, ai-security, automation, autonomous-pentesting and bug-bounty.

Documentation

README

Excerpt

Exploiting Format String Vulnerabilities

When to Use

During authorized binary/exploitation assessments when attacker input is passed as the first argument (the format) to printf, fprintf, sprintf, snprintf, vprintf, syslog, or similar.
When you need a memory-disclosure primitive to leak stack contents, a libc/PIE pointer, or a stack canary to defeat ASLR/PIE/canary protections.
When you have an arbitrary-write primitive opportunity via %n/%hn to overwrite a GOT entry, .fini_array, a saved return address, or a function pointer.
On Windows x64 services where a buggy _snprintf(dst, len, attacker_fmt) call provides no varargs and conversions read pointers out of RCX/RDX/R8/R9 registers.

Critical: Concepts/Steps Most Often Missed

This is the opening of the README. Read the full README on GitHub.

Frequently asked about Format String Exploitation

What else does xalgord publish alongside Format String Exploitation?
Format String Exploitation is one of 51 skills that DirSkills catalogs from xalgord/xalgorix, the repository it ships in. Its siblings there include AFL++ Fuzzing, AI Security Guardrails and AI-Assisted Vulnerability Discovery. Each one is a separate skill with its own page in this directory, installs the same way Format String Exploitation does, and is maintained by xalgord in that same repository. The rest of the collection is listed on the xalgord/xalgorix page.
How does Format String Exploitation compare to other Quality skills?
Format String Exploitation ranks #924 by stars among the 1354 Quality skills in this catalog. The most-starred ones next to it are Benchmark, Benchmark Optimization Loop and API Design Patterns. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Format String Exploitation against them. Open each page to compare what they document and how they install.