leviathan
c63ee72aa1
Adds docs/JSON_SCHEMA.md documenting the shape and stability promises
of the JSON document --scan --json emits on stdout. The schema is
already what the binary produces — this commit pins the contract so
fleet-scan / SIEM consumers can rely on it across releases.
What it covers:
- Top-level object: { version, modules } and field stability.
- Per-module entry: { name, cve, result } with type + stability.
- The 6-value result enum (OK / TEST_ERROR / VULNERABLE /
EXPLOIT_FAIL / PRECOND_FAIL / EXPLOIT_OK) and what each means
semantically.
- Process exit-code semantics for --scan (worst observed result
becomes the exit code — lets a SIEM treat the binary exit as a
single-host alert level).
- Bash + jq one-liners for the common fleet-roll-up patterns.
- A recommended Python consumer pattern with the forward-compat
guidance (ignore unknown fields, treat unknown result strings as
TEST_ERROR-equivalent).
- Explicit stability promises: which fields cannot change without
a major-version bump, what may be added in future minor
releases, what consumers MUST tolerate.
Verified against the live binary: --scan --json produces exactly
the documented shape (top-level keys {modules, version}; per-module
keys {cve, name, result}; result values come from the documented
enum). 31 modules / 30 unique CVEs at v0.5.0.
README's 'Sysadmins' audience row now links the schema doc:
'JSON output for CI gates ([schema](docs/JSON_SCHEMA.md))'.
213 lines
9.3 KiB
Markdown
213 lines
9.3 KiB
Markdown
# SKELETONKEY
|
||
|
||
[](https://github.com/KaraZajac/SKELETONKEY/releases/latest)
|
||
[](LICENSE)
|
||
[](CVES.md)
|
||
[](#)
|
||
|
||
> **One curated binary. 28 verified Linux LPE exploits, 2016 → 2026
|
||
> (+3 ported-but-unverified). Detection rules in the box. One command
|
||
> picks the safest one and runs it.**
|
||
|
||
```bash
|
||
curl -sSL https://github.com/KaraZajac/SKELETONKEY/releases/latest/download/install.sh | sh \
|
||
&& skeletonkey --auto --i-know
|
||
```
|
||
|
||
> ⚠️ **Authorized testing only.** SKELETONKEY runs real exploits. By
|
||
> using it you assert you have explicit authorization to test the
|
||
> target system. See [`docs/ETHICS.md`](docs/ETHICS.md).
|
||
|
||
## Why use this
|
||
|
||
Most Linux privesc tooling is broken in one of three ways:
|
||
|
||
- **`linux-exploit-suggester` / `linpeas`** — tell you what *might*
|
||
work, run nothing
|
||
- **`auto-root-exploit` / `kernelpop`** — bundle exploits but ship
|
||
no detection signatures and went stale years ago
|
||
- **Per-CVE PoC repos** — one author, one distro, abandoned within
|
||
months
|
||
|
||
SKELETONKEY is one binary, actively maintained, with detection rules
|
||
for every CVE in the bundle — same project for red and blue teams.
|
||
|
||
## Who it's for
|
||
|
||
| Audience | What you get |
|
||
|---|---|
|
||
| **Red team / pentesters** | One tested binary. `--auto` ranks vulnerable modules by safety and runs the safest. Honest scope reporting — never claims root it didn't actually get. |
|
||
| **Sysadmins** | `skeletonkey --scan` (no sudo needed) tells you which boxes still need patching. Fleet-scan tool included. JSON output for CI gates ([schema](docs/JSON_SCHEMA.md)). |
|
||
| **Blue team / SOC** | Auditd + sigma + yara + falco rules for every CVE. `--detect-rules --format=auditd \| sudo tee …` ships SIEM coverage in one command. |
|
||
| **CTF / training** | Reproducible LPE environment with public CVEs across a 10-year timeline. Each module documents the bug, the trigger, and the fix. |
|
||
|
||
## Corpus at a glance
|
||
|
||
**28 verified modules** spanning the 2016 → 2026 LPE timeline, plus
|
||
**3 ported-but-unverified** modules (`dirtydecrypt`, `fragnesia`,
|
||
`pack2theroot` — see note below):
|
||
|
||
| Tier | Count | What it means |
|
||
|---|---|---|
|
||
| 🟢 Full chain | **14** | Lands root (or its canonical capability) end-to-end. No per-kernel offsets needed. |
|
||
| 🟡 Primitive | **14** | Fires the kernel primitive + grooms the slab + records a witness. Default returns `EXPLOIT_FAIL` honestly. Pass `--full-chain` to engage the shared `modprobe_path` finisher (needs offsets — see [`docs/OFFSETS.md`](docs/OFFSETS.md)). |
|
||
| ⚪ Ported, unverified | **3** | `dirtydecrypt`, `fragnesia`, `pack2theroot`. Built and registered with **version-pinned `detect()`** (Linux 7.0 / 7.0.9 / PackageKit 1.3.5 respectively), but the **exploit bodies** are not yet validated end-to-end. `--auto` auto-enables `--active` to confirm empirically on top of the version verdict. Excluded from the 28-module verified counts above. |
|
||
|
||
**🟢 Modules that land root on a vulnerable host:**
|
||
copy_fail family ×5 · dirty_pipe · dirty_cow · pwnkit · overlayfs
|
||
(CVE-2021-3493) · overlayfs_setuid (CVE-2023-0386) ·
|
||
cgroup_release_agent · ptrace_traceme · sudoedit_editor · entrybleed
|
||
(KASLR leak primitive)
|
||
|
||
**🟡 Modules with opt-in `--full-chain`:**
|
||
af_packet · af_packet2 · af_unix_gc · cls_route4 · fuse_legacy ·
|
||
nf_tables · nft_set_uaf · nft_fwd_dup · nft_payload ·
|
||
netfilter_xtcompat · stackrot · sudo_samedit · sequoia · vmwgfx
|
||
|
||
**⚪ Ported-but-unverified (not in the counts above):**
|
||
dirtydecrypt (CVE-2026-31635) · fragnesia (CVE-2026-46300) ·
|
||
pack2theroot (CVE-2026-41651) — ported from public PoCs, **exploit
|
||
bodies not yet VM-validated**. All three have version-pinned `detect()`:
|
||
`dirtydecrypt` against mainline fix commit `a2567217` in Linux 7.0;
|
||
`fragnesia` against mainline 7.0.9 (older Debian-stable branches still
|
||
unfixed); `pack2theroot` against PackageKit fix release 1.3.5
|
||
(commit `76cfb675`), version read from the daemon over D-Bus.
|
||
`--auto` auto-enables `--active` to confirm empirically on top.
|
||
|
||
See [`CVES.md`](CVES.md) for per-module CVE, kernel range, and
|
||
detection status.
|
||
|
||
## Quickstart
|
||
|
||
```bash
|
||
# Install (x86_64 / arm64; checksum-verified)
|
||
curl -sSL https://github.com/KaraZajac/SKELETONKEY/releases/latest/download/install.sh | sh
|
||
|
||
# What's this box vulnerable to? (no sudo)
|
||
skeletonkey --scan
|
||
|
||
# Pick the safest LPE and run it
|
||
skeletonkey --auto --i-know
|
||
|
||
# Deploy detection rules (needs sudo to write into /etc/audit/rules.d/)
|
||
skeletonkey --detect-rules --format=auditd \
|
||
| sudo tee /etc/audit/rules.d/99-skeletonkey.rules
|
||
|
||
# Fleet scan — many hosts via SSH, aggregated JSON for SIEM
|
||
./tools/skeletonkey-fleet-scan.sh --binary skeletonkey \
|
||
--ssh-key ~/.ssh/id_rsa hosts.txt
|
||
```
|
||
|
||
**SKELETONKEY runs as a normal unprivileged user** — that's the point.
|
||
`--scan`, `--audit`, `--exploit`, and `--detect-rules` all work without
|
||
`sudo`. Only `--mitigate` and rule-file installation write root-owned
|
||
paths.
|
||
|
||
### Example: unprivileged → root
|
||
|
||
```text
|
||
$ id
|
||
uid=1000(kara) gid=1000(kara) groups=1000(kara)
|
||
|
||
$ skeletonkey --auto --i-know
|
||
[*] auto: host=demo distro=ubuntu/24.04 kernel=5.15.0-56-generic arch=x86_64
|
||
[*] auto: active probes enabled — brief /tmp file touches and fork-isolated namespace probes
|
||
[*] auto: scanning 31 modules for vulnerabilities...
|
||
[+] auto: dirty_pipe VULNERABLE (safety rank 90)
|
||
[+] auto: cgroup_release_agent VULNERABLE (safety rank 98)
|
||
[+] auto: pwnkit VULNERABLE (safety rank 100)
|
||
[ ] auto: copy_fail patched or not applicable
|
||
[ ] auto: nf_tables precondition not met
|
||
...
|
||
|
||
[*] auto: scan summary — 3 vulnerable, 21 patched/n.a., 7 precondition-fail, 0 indeterminate
|
||
[*] auto: 3 vulnerable modules found. Safest is 'pwnkit' (rank 100).
|
||
[*] auto: launching --exploit pwnkit...
|
||
|
||
[+] pwnkit: writing gconv-modules cache + payload.so...
|
||
[+] pwnkit: execve(pkexec) with NULL argv + crafted envp...
|
||
# id
|
||
uid=0(root) gid=0(root) groups=0(root)
|
||
```
|
||
|
||
The safety ranking goes: **structural escapes** (no kernel state
|
||
touched) → **page-cache writes** → **userspace cred-races** →
|
||
**kernel primitives** → **kernel races** (least predictable). The
|
||
goal is to never crash a production box looking for root.
|
||
|
||
## How it works
|
||
|
||
Each CVE (or tightly-related family) is a **module** under `modules/`.
|
||
Modules export a standard interface (`detect / exploit / mitigate /
|
||
cleanup`) plus metadata (kernel range, detection rule text). The
|
||
top-level binary dispatches per command:
|
||
|
||
- `--scan` walks every module's `detect()` against the running host
|
||
- `--exploit <name> --i-know` runs the named module's exploit (the
|
||
`--i-know` flag is the authorization gate)
|
||
- `--auto --i-know` does the scan, ranks by safety, runs the safest
|
||
- `--detect-rules --format=<auditd|sigma|yara|falco>` emits the
|
||
embedded rule corpus
|
||
- `--mitigate <name>` / `--cleanup <name>` apply / undo temporary
|
||
mitigations (module-dependent — most kernel modules say "upgrade")
|
||
- `--dump-offsets` reads `/proc/kallsyms` + `/boot/System.map` and
|
||
emits a ready-to-paste C entry for the `--full-chain` offset table
|
||
|
||
See [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) for the
|
||
module-loader design.
|
||
|
||
## The verified-vs-claimed bar
|
||
|
||
Most public PoC repos hardcode offsets for one kernel build and
|
||
silently break elsewhere. SKELETONKEY refuses to ship fabricated
|
||
offsets. The shared `--full-chain` finisher only returns
|
||
`EXPLOIT_OK` after a setuid bash sentinel file *actually appears*;
|
||
otherwise modules return `EXPLOIT_FAIL` with a diagnostic. Operators
|
||
populate the offset table once per target kernel via
|
||
`skeletonkey --dump-offsets` and either set env vars or upstream the
|
||
entry via PR ([`CONTRIBUTING.md`](CONTRIBUTING.md)).
|
||
|
||
## Build from source
|
||
|
||
```bash
|
||
git clone https://github.com/KaraZajac/SKELETONKEY.git
|
||
cd SKELETONKEY
|
||
make
|
||
./skeletonkey --version
|
||
```
|
||
|
||
Builds clean with gcc or clang on any modern Linux. macOS dev builds
|
||
also compile (modules with Linux-only headers stub out gracefully).
|
||
|
||
## Status
|
||
|
||
**v0.5.0 cut 2026-05-17.** 28 verified modules, plus 3
|
||
ported-but-unverified (`dirtydecrypt`, `fragnesia`, `pack2theroot`)
|
||
added since the cut. All 31 build clean on Debian 13 (kernel 6.12)
|
||
and refuse cleanly on patched hosts. `--auto` now auto-enables
|
||
`--active` and runs each `detect()` in a fork-isolated child so one
|
||
crashing probe cannot tear down the scan. Empirical end-to-end
|
||
validation on a vulnerable-target VM matrix is the next roadmap item;
|
||
until then, the corpus is best understood as "compiles + detects +
|
||
structurally correct + honest on failure" — and the three ported
|
||
modules have not been run against a vulnerable target at all.
|
||
|
||
See [`ROADMAP.md`](ROADMAP.md) for the next planned modules and
|
||
infrastructure work.
|
||
|
||
## Contributing
|
||
|
||
PRs welcome for: kernel offsets (run `--dump-offsets` on a target
|
||
kernel, paste into `core/offsets.c`), new modules, detection rules,
|
||
and CVE-status corrections. See [`CONTRIBUTING.md`](CONTRIBUTING.md).
|
||
|
||
## Acknowledgments
|
||
|
||
Each module credits the original CVE reporter and PoC author in its
|
||
`NOTICE.md`. SKELETONKEY is the bundling and bookkeeping layer;
|
||
the research credit belongs to the people who found the bugs.
|
||
|
||
## License
|
||
|
||
MIT — see [`LICENSE`](LICENSE).
|