Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add allsmog/pwn-claude-plugin/plugin install pwn-htbWrote 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/allsmog/pwn-claude-plugin/heap-exploitation)<a href="https://agentmods.dev/skills/allsmog/pwn-claude-plugin/heap-exploitation"><img src="https://agentmods.dev/badge/skills/allsmog/pwn-claude-plugin/heap-exploitation/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/allsmog/pwn-claude-plugin/heap-exploitation"><img src="https://agentmods.dev/badge/skills/allsmog/pwn-claude-plugin/heap-exploitation.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 | $0.00087 | $0.02143 |
| Opus 5 | $0.00044 | $0.01071 |
| Sonnet 5 | $0.00017 | $0.00429 |
| Haiku 4.5 | $0.00009 | $0.00214 |
Grade A, and why
Heap Exploitation 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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 316 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Heap Exploitation
Overview
Heap exploitation targets vulnerabilities in dynamic memory allocation (malloc/free). This skill covers glibc heap internals, common vulnerabilities, and exploitation techniques from basic to advanced.
Prerequisites
- Understanding of C memory management
- GDB with pwndbg (for heap visualization)
- Knowledge of basic binary exploitation
- Familiarity with pwntools
Heap Internals Quick Reference
Chunk Structure
┌──────────────────┐
│ prev_size │ ← Only if previous chunk is free
├──────────────────┤
│ size | AMP │ ← A=allocated, M=mmap, P=prev_inuse
├──────────────────┤
│ user data │ ← Returned by malloc()
│ ... │
└──────────────────┘
Free Chunk (adds fd/bk pointers)
┌──────────────────┐
│ prev_size │
├──────────────────┤
│ size │
├──────────────────┤
│ fd │ ← Forward pointer to next free chunk
├──────────────────┤
│ bk │ ← Back pointer to previous free chunk
├──────────────────┤
│ (fd_nextsize) │ ← Only for large chunks
├──────────────────┤
│ (bk_nextsize) │ ← Only for large chunks
└──────────────────┘
Bin Types
| Bin | Size Range | Behavior | Security |
|---|---|---|---|
| Tcache | 0x20-0x410 | Per-thread LIFO | Minimal (< 2.32) |
| Fastbin | 0x20-0x80 | Global LIFO | Size check only |
| Unsorted | Any | Temporary holding | Some checks |
| Small | < 0x400 | FIFO by size | FIFO checks |
| Large | >= 0x400 | Best fit | Complex checks |
Vulnerability Types
1. Use-After-Free (UAF)
Access freed memory - can leak or corrupt heap metadata.
Detection pattern:
free(ptr);
// ptr not nullified
ptr->field = value; // UAF write
data = ptr->field; // UAF read
2. Double Free
Free the same chunk twice - corrupts free lists.
Detection pattern:
free(ptr);
// ...
free(ptr); // Same pointer freed again
3. Heap Overflow
Write beyond chunk boundary into adjacent chunks.
What ships with it
2 files 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.
- 10d ago First seen · 316 lines · 87 tokens per session scan A 6bab7751b203
Heap Exploitation is a skill published in the GitHub repository allsmog/pwn-claude-plugin (2 stars, last pushed 6mo ago), licensed MIT. It adds 87 tokens to every session and 2,143 once invoked, about $0.0004 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 2026-08-31.
Other skills, from other repositories
bypassing-binary-exploitation-mitigations
Methodology for identifying and defeating common binary hardening mitigations during authorized exploitation — ASLR, PIE, stack canaries, NX/DEP, and RELRO — by leaking addresses, brute-forcing entropy, abusing forked-process behavior, and selecting the right code-reuse primitive for the protections in place.
exploiting-arbitrary-write-to-execution
Methodology for converting an arbitrary-write (write-what-where) or write-anything-anywhere primitive into code execution during authorized engagements, covering target selection among GOT/PLT entries, .finiarray/.dtors, mallochook/freehook, the atexit/exitfuncs handler list, and printfarginfotable, plus how…
exploiting-format-string-vulnerabilities
Methodology for exploiting format string bugs where attacker-controlled data reaches the format argument of printf-family functions, enabling stack/memory disclosure (info leaks for ASLR/PIE/canary defeat) and arbitrary write primitives (%n) to hijack control flow via GOT/.finiarray overwrites.
exploiting-glibc-heap-vulnerabilities
Methodology for exploiting glibc ptmalloc2 heap vulnerabilities during authorized engagements — use-after-free, double-free, heap overflow, and bin-based attacks (tcache poisoning, fast-bin dup, unsorted/large-bin) — including modern mitigations (tcache key, safe-linking, hook removal) and how to obtain leaks and…
exploiting-linux-kernel-vulnerabilities
Methodology for discovering and exploiting Linux kernel memory-corruption vulnerabilities (UAF, OOB read/write, race/TOCTOU, type confusion) during authorized engagements, covering reachability analysis, building stable read/write primitives from a single bug, defeating KASLR/SMEP/SMAP/KPTI, slab/buddy heap grooming…
exploiting-stack-buffer-overflows
Methodology for discovering and exploiting stack-based buffer overflows in native binaries during authorized engagements, covering crash triage, offset discovery with De Bruijn patterns, control of the saved return address, and escalation paths (ret2win, stack shellcode, ROP) depending on which mitigations are present.