# Exploit Development

> Use when turning a memory-corruption bug into a working PoC — stack/ROP, glibc heap & FSOP, format strings, browser/JIT type confusion & UAF, Linux/Windows kernel LPE against ASLR/DEP/CFG/CET/V8-Sandbox

- Skill: `netvar1337/exploit-development` (Agent Skill, multi-file: 16 files)
- Install (CLI): `npx skillmds@latest add netvar1337/exploit-development`
- Raw SKILL.md: https://api.skillmd.com/api/skills/netvar1337/exploit-development/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: netvar1337 (https://skillmd.com/u/netvar1337)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/netvar1337/exploit-development

---


# Exploit Development

End-to-end weaponization: turn a confirmed bug class into a reliable, version-pinned PoC, then a primitive chain (leak -> R/W -> control flow), against current mitigations. Every cluster pairs the offensive path with detection telemetry and OPSEC.

## When to Activate

- A confirmed vulnerability needs a working, reliable PoC (>=90% success target).
- Userland binary exploitation: stack overflow, heap (UAF/overflow/double-free), format string.
- Defeating modern mitigations: ASLR/PIE, NX/DEP, stack canaries, Full RELRO, CFG, Intel CET shadow stack, V8 Sandbox/pointer compression.
- Browser/JIT engine exploitation (V8 type confusion, addrof/fakeobj, WASM jump-table pivot).
- Local privilege escalation via Linux/Windows kernel memory corruption.
- Converting a crash into a stable read/write/execute primitive chain.

## Technique Map

| Technique | ATT&CK | CWE | Reference | Script |
|-----------|--------|-----|-----------|--------|
| Stack overflow -> ret2libc/ROP | T1203 | CWE-121 | references/stack-rop-mitigations.md | scripts/offset_finder.py |
| ret2csu / SROP / stack pivot | T1203 | CWE-121 | references/stack-rop-mitigations.md | scripts/rop_autochain.py |
| ret2dlresolve (leakless) | T1203 | CWE-121 | references/stack-rop-mitigations.md | scripts/rop_autochain.py |
| CET/CFG-aware control-flow hijack | T1203 | CWE-1419 | references/stack-rop-mitigations.md | scripts/rop_autochain.py |
| tcache/fastbin poisoning + safe-linking | T1203 | CWE-416 | references/heap-glibc-fsop.md | scripts/safe_linking.py |
| House of Botcake / Einherjar / Apple2 | T1203 | CWE-415 | references/heap-glibc-fsop.md | scripts/heap_fsop.py |
| FSOP (stdout leak, House of Apple 2) | T1203 | CWE-787 | references/heap-glibc-fsop.md | scripts/heap_fsop.py |
| Format string leak + arbitrary write | T1203 | CWE-134 | references/format-string-leaks.md | scripts/fmtstr_leak.py |
| V8 type confusion -> addrof/fakeobj | T1203 | CWE-843 | references/browser-jit-uaf.md | scripts/v8_primitives.js |
| V8 Sandbox escape (WASM jump table) | T1203 | CWE-843 | references/browser-jit-uaf.md | scripts/v8_primitives.js |
| UAF heap-spray reclaim | T1203 | CWE-416 | references/browser-jit-uaf.md | scripts/v8_primitives.js |
| Linux kernel UAF -> cross-cache | T1068 | CWE-416 | references/kernel-exploitation.md | scripts/kernel_lpe_skeleton.c |
| Dirty Pagetable / Pagedirectory | T1068 | CWE-416 | references/kernel-exploitation.md | scripts/kernel_lpe_skeleton.c |
| msg_msg infoleak / spray | T1068 | CWE-125 | references/kernel-exploitation.md | scripts/kernel_lpe_skeleton.c |
| Windows PreviousMode / I/O Ring R/W | T1068 | CWE-787 | references/kernel-exploitation.md | scripts/kernel_lpe_skeleton.c |
| Empirical mitigation matrix (build witness under N profiles) | T1203 | CWE-693 | references/exploit-feasibility.md | scripts/feasibility_profile.py |
| Cached context + blocked-technique gate for /exploit | T1203 | CWE-693 | references/exploit-feasibility.md | scripts/exploit_context.py |

## Quick Start

```bash
# 0. Fingerprint target + libc (pin every version)
file ./target; pwn checksec ./target
strings -a libc.so.6 | grep -m1 'release version'   # exact glibc build
patchelf --set-interpreter ./ld.so --replace-needed libc.so.6 ./libc.so.6 ./target

# 1. Crash + offset (cyclic) — see scripts/offset_finder.py
python3 scripts/offset_finder.py ./target            # auto pattern_create/offset

# 2. Gadgets + one_gadget
ROPgadget --binary ./libc.so.6 > gadgets.txt
ropper -f ./libc.so.6 --search 'pop rdi; ret'
one_gadget ./libc.so.6

# 3. Build chain (leak -> base -> system/execve) — scripts/rop_autochain.py
python3 scripts/rop_autochain.py ./target ./libc.so.6 --leak puts --remote host:port

# 4. Heap targets: poison fd with safe-linking math, FSOP for the endgame
python3 scripts/safe_linking.py --chunk 0x55...000 --target 0x7f...   # encrypt fd
python3 scripts/heap_fsop.py --libc ./libc.so.6 --mode apple2         # FSOP payload

# 5. Verify reliability before delivery
for i in $(seq 1 50); do python3 exploit.py >/dev/null 2>&1 && echo ok; done | wc -l
```

> **Cache the target context once.** Steps 0–2 (file/checksec/libc build, gadget table,
> one_gadget) describe the *target*, not a single attempt — compute them once and reuse them across
> every PoC iteration. Re-running recon on each attempt wastes budget and pollutes telemetry; an
> autopilot loop should treat the fingerprint + gadget set as cached input, not a per-iteration step.
> A future empirical **feasibility profile** (raptor-adoption PR-3) will rebuild the crash witness
> under several mitigation profiles and emit a machine-readable map of which techniques the target
> actually permits — the PoC is then forbidden from using a technique that map marks blocked. Until
> it lands: record the checksec/mitigation state explicitly and do not claim a technique the target's
> protections rule out.

## OPSEC & Detection (summary)

| Technique | Telemetry/IOC | Detection (Sigma/EDR) | OPSEC note |
|-----------|---------------|-----------------------|------------|
| ROP/ret2libc | Stack exec faults, abnormal `execve("/bin/sh")` child of network daemon | EDR: child shell from listener; auditd `execve` of `/bin/sh` w/ empty argv | Use in-memory ORW (open/read/write flag) instead of shell to avoid `execve` IOC |
| Heap/FSOP | glibc `*** stack smashing ***`/`malloc(): ...` aborts in logs; SIGABRT crash loops | Sigma: repeated SIGABRT/SIGSEGV from same PID; coredump bursts | Disable coredumps (`prctl(PR_SET_DUMPABLE,0)`); tune spray to avoid abort()s |
| Format string | `%n`/`%p` strings in request/argv logs; segfault on bad write | WAF/Sigma on `%n`,`%[0-9]+\$n` in inputs | Pre-stage write target; minimize `%` count, avoid huge field widths |
| V8 type confusion | Renderer crash dumps, `chrome_crashpad`, GPU/renderer restarts | Crashpad telemetry; EDR on renderer spawning unexpected processes | Keep corruption inside cage; clean up sprayed arrays; avoid renderer crash on failure |
| Kernel LPE | `dmesg` oops/RIP, KASAN splats, `apparmor`/`audit` LPE child = root | Sigma: process gaining uid=0 w/o setuid path; EDR kernel-callback | Fileless (no SUID drop); restore corrupted state; clear `dmesg` only if authorized |

## Deep Dives

- references/stack-rop-mitigations.md — Stack overflow, ret2libc/ROP, ret2csu, SROP, stack pivots, ret2dlresolve; defeating ASLR/PIE/NX/canary/RELRO and CET shadow stack / CFG-aware constraints. Backed by `offset_finder.py`, `rop_autochain.py`.
- references/heap-glibc-fsop.md — glibc 2.35-2.40 internals, tcache/fastbin poisoning under safe-linking, House of Botcake/Einherjar/Apple 2/Tangerine, stdout FSOP leak, post-hook-removal endgames. Backed by `safe_linking.py`, `heap_fsop.py`.
- references/format-string-leaks.md — Read/write mechanics, stack-arg indexing, `%n` arbitrary write, PIE/libc/canary leaks, fmtstr automation and one-shot GOT/exit-handler overwrite. Backed by `fmtstr_leak.py`.
- references/browser-jit-uaf.md — V8 element-kind confusion, addrof/fakeobj, arbitrary R/W under pointer compression, 2024-2025 Maglev/TurboFan CVEs, V8 Sandbox escape via WASM jump table, generic UAF reclaim. Backed by `v8_primitives.js`.
- references/kernel-exploitation.md — Linux UAF/cross-cache, Dirty Pagetable/Pagedirectory (CVE-2024-1086), msg_msg leak/spray, SLUBStick; Windows pool spray, PreviousMode + I/O Ring R/W, CLFS/AFD CVEs. Backed by `kernel_lpe_skeleton.c`.
- references/exploit-feasibility.md — empirical mitigation matrix: rebuild the crash witness under permissive/distro/hardened/asan profiles, record which still fire, derive the blocked-technique map; `/exploit` is forbidden a technique the map marks blocked. Backed by `feasibility_profile.py` (build/replay, Linux/devcontainer) + `exploit_context.py` (cached checksec/libc + the `assert_allowed` gate). Pairs with `reverse-engineering/references/rr-time-travel.md` + `coverage-reachability.md`.