leviathan
df4b879527
Standalone Python script that pulls Debian's security-tracker JSON
and compares each module's hardcoded kernel_patched_from table
against the fixed-versions Debian actually ships. Surfaces real
drift the no-fabrication rule needs us to fix:
MISSING — Debian has a fix on a kernel branch we have no entry
for. Module's detect() would say VULNERABLE on a host
that's actually patched.
TOO_TIGHT — Our threshold is later than Debian's earliest fix on
the same branch. Module would call a patched host
VULNERABLE. False-positive on production fleets.
INFO — Our threshold is earlier than Debian's. We're more
permissive; usually fine (we tracked a different
upstream-stable cut), but flagged for review.
Three output modes:
default (text) — human-readable report on stderr
--json — machine-readable for CI / dashboards
--patch — unified-diff-style proposed C-source edits
--refresh — bypass the 12h cache TTL and re-fetch
Implementation:
- urllib (no pip deps) fetches the ~70MB tracker JSON.
- Cached at /tmp/skeletonkey-debian-tracker.json with 12h TTL.
- Parses every modules/*/skeletonkey_modules.c for the .cve = '...'
field + the kernel_patched_from <name>[] = { {M,m,p}, ... } array.
- Per CVE, builds {debian_release -> upstream_version_tuple} from
the tracker's 'releases.*.fixed_version' field (stripping Debian
-N / +bN / ~bpoN suffixes to recover the upstream version).
- Groups by (major, minor) branch; flags MISSING / TOO_TIGHT / INFO.
- Exits non-zero when MISSING or TOO_TIGHT findings exist (suitable
for a CI 'detect-drift' job).
First-run output found drift in 17 of 20 modules with kernel_range
tables — operator-reviewable. NOT auto-applied; this commit only
ships the diagnostic tool, not the suggested fixes.
README's Contributing section now points at the tool.
238 lines
10 KiB
Markdown
238 lines
10 KiB
Markdown
# SKELETONKEY
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[](https://github.com/KaraZajac/SKELETONKEY/releases/latest)
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[](LICENSE)
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[](CVES.md)
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[](#)
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> **One curated binary. 28 verified Linux LPE exploits, 2016 → 2026
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> (+3 ported-but-unverified). Detection rules in the box. One command
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> picks the safest one and runs it.**
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```bash
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curl -sSL https://github.com/KaraZajac/SKELETONKEY/releases/latest/download/install.sh | sh \
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&& skeletonkey --auto --i-know
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```
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> ⚠️ **Authorized testing only.** SKELETONKEY runs real exploits. By
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> using it you assert you have explicit authorization to test the
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> target system. See [`docs/ETHICS.md`](docs/ETHICS.md).
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## Why use this
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Most Linux privesc tooling is broken in one of three ways:
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- **`linux-exploit-suggester` / `linpeas`** — tell you what *might*
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work, run nothing
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- **`auto-root-exploit` / `kernelpop`** — bundle exploits but ship
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no detection signatures and went stale years ago
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- **Per-CVE PoC repos** — one author, one distro, abandoned within
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months
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SKELETONKEY is one binary, actively maintained, with detection rules
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for every CVE in the bundle — same project for red and blue teams.
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## Who it's for
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| Audience | What you get |
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|---|---|
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| **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. |
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| **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)). |
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| **Blue team / SOC** | Auditd + sigma + yara + falco rules for every CVE. `--detect-rules --format=auditd \| sudo tee …` ships SIEM coverage in one command. |
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| **CTF / training** | Reproducible LPE environment with public CVEs across a 10-year timeline. Each module documents the bug, the trigger, and the fix. |
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## Corpus at a glance
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**28 verified modules** spanning the 2016 → 2026 LPE timeline, plus
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**3 ported-but-unverified** modules (`dirtydecrypt`, `fragnesia`,
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`pack2theroot` — see note below):
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| Tier | Count | What it means |
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|---|---|---|
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| 🟢 Full chain | **14** | Lands root (or its canonical capability) end-to-end. No per-kernel offsets needed. |
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| 🟡 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)). |
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| ⚪ 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. |
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**🟢 Modules that land root on a vulnerable host:**
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copy_fail family ×5 · dirty_pipe · dirty_cow · pwnkit · overlayfs
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(CVE-2021-3493) · overlayfs_setuid (CVE-2023-0386) ·
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cgroup_release_agent · ptrace_traceme · sudoedit_editor · entrybleed
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(KASLR leak primitive)
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**🟡 Modules with opt-in `--full-chain`:**
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af_packet · af_packet2 · af_unix_gc · cls_route4 · fuse_legacy ·
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nf_tables · nft_set_uaf · nft_fwd_dup · nft_payload ·
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netfilter_xtcompat · stackrot · sudo_samedit · sequoia · vmwgfx
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**⚪ Ported-but-unverified (not in the counts above):**
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dirtydecrypt (CVE-2026-31635) · fragnesia (CVE-2026-46300) ·
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pack2theroot (CVE-2026-41651) — ported from public PoCs, **exploit
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bodies not yet VM-validated**. All three have version-pinned `detect()`:
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`dirtydecrypt` against mainline fix commit `a2567217` in Linux 7.0;
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`fragnesia` against mainline 7.0.9 (older Debian-stable branches still
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unfixed); `pack2theroot` against PackageKit fix release 1.3.5
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(commit `76cfb675`), version read from the daemon over D-Bus.
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`--auto` auto-enables `--active` to confirm empirically on top.
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See [`CVES.md`](CVES.md) for per-module CVE, kernel range, and
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detection status.
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## Quickstart
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```bash
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# Install (x86_64 / arm64; checksum-verified)
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curl -sSL https://github.com/KaraZajac/SKELETONKEY/releases/latest/download/install.sh | sh
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# What's this box vulnerable to? (no sudo)
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skeletonkey --scan
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# Pick the safest LPE and run it
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skeletonkey --auto --i-know
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# Deploy detection rules (needs sudo to write into /etc/audit/rules.d/)
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skeletonkey --detect-rules --format=auditd \
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| sudo tee /etc/audit/rules.d/99-skeletonkey.rules
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# Fleet scan — many hosts via SSH, aggregated JSON for SIEM
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./tools/skeletonkey-fleet-scan.sh --binary skeletonkey \
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--ssh-key ~/.ssh/id_rsa hosts.txt
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```
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**SKELETONKEY runs as a normal unprivileged user** — that's the point.
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`--scan`, `--audit`, `--exploit`, and `--detect-rules` all work without
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`sudo`. Only `--mitigate` and rule-file installation write root-owned
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paths.
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### Example: unprivileged → root
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```text
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$ id
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uid=1000(kara) gid=1000(kara) groups=1000(kara)
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$ skeletonkey --auto --i-know
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[*] auto: host=demo distro=ubuntu/24.04 kernel=5.15.0-56-generic arch=x86_64
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[*] auto: active probes enabled — brief /tmp file touches and fork-isolated namespace probes
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[*] auto: scanning 31 modules for vulnerabilities...
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[+] auto: dirty_pipe VULNERABLE (safety rank 90)
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[+] auto: cgroup_release_agent VULNERABLE (safety rank 98)
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[+] auto: pwnkit VULNERABLE (safety rank 100)
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[ ] auto: copy_fail patched or not applicable
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[ ] auto: nf_tables precondition not met
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...
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[*] auto: scan summary — 3 vulnerable, 21 patched/n.a., 7 precondition-fail, 0 indeterminate
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[*] auto: 3 vulnerable modules found. Safest is 'pwnkit' (rank 100).
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[*] auto: launching --exploit pwnkit...
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[+] pwnkit: writing gconv-modules cache + payload.so...
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[+] pwnkit: execve(pkexec) with NULL argv + crafted envp...
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# id
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uid=0(root) gid=0(root) groups=0(root)
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```
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The safety ranking goes: **structural escapes** (no kernel state
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touched) → **page-cache writes** → **userspace cred-races** →
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**kernel primitives** → **kernel races** (least predictable). The
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goal is to never crash a production box looking for root.
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## How it works
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Each CVE (or tightly-related family) is a **module** under `modules/`.
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Modules export a standard interface (`detect / exploit / mitigate /
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cleanup`) plus metadata (kernel range, detection rule text). The
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top-level binary dispatches per command:
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- `--scan` walks every module's `detect()` against the running host
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- `--exploit <name> --i-know` runs the named module's exploit (the
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`--i-know` flag is the authorization gate)
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- `--auto --i-know` does the scan, ranks by safety, runs the safest
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- `--detect-rules --format=<auditd|sigma|yara|falco>` emits the
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embedded rule corpus
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- `--mitigate <name>` / `--cleanup <name>` apply / undo temporary
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mitigations (module-dependent — most kernel modules say "upgrade")
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- `--dump-offsets` reads `/proc/kallsyms` + `/boot/System.map` and
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emits a ready-to-paste C entry for the `--full-chain` offset table
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See [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) for the
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module-loader design.
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## The verified-vs-claimed bar
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Most public PoC repos hardcode offsets for one kernel build and
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silently break elsewhere. SKELETONKEY refuses to ship fabricated
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offsets. The shared `--full-chain` finisher only returns
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`EXPLOIT_OK` after a setuid bash sentinel file *actually appears*;
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otherwise modules return `EXPLOIT_FAIL` with a diagnostic. Operators
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populate the offset table once per target kernel via
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`skeletonkey --dump-offsets` and either set env vars or upstream the
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entry via PR ([`CONTRIBUTING.md`](CONTRIBUTING.md)).
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## Build from source
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```bash
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git clone https://github.com/KaraZajac/SKELETONKEY.git
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cd SKELETONKEY
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make
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./skeletonkey --version
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```
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Builds clean with gcc or clang on any modern Linux. macOS dev builds
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also compile (modules with Linux-only headers stub out gracefully).
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## Status
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**v0.6.0 cut 2026-05-23.** 28 verified modules, plus 3
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ported-but-unverified (`dirtydecrypt`, `fragnesia`, `pack2theroot`).
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All 31 build clean on Debian 13 (kernel 6.12) and refuse cleanly on
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patched hosts.
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Reliability + accuracy work in v0.6.0:
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- Shared **host fingerprint** (`core/host.{h,c}`) populated once at
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startup — kernel/distro/userns gates/sudo+polkit versions — exposed
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to every module via `ctx->host`. 26 of 27 distinct modules consume it.
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- **Test harness** (`tests/test_detect.c`, `make test`) — 44 unit
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tests over mocked host fingerprints; runs as a non-root user in CI.
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- `--auto` upgrades: auto-enables `--active`, per-detect 15s timeout,
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fork-isolated detect + exploit so a crashing module can't tear down
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the dispatcher, structured per-module verdict table, scan summary.
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- `--dry-run` flag (preview without firing; no `--i-know` needed).
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- Pinned mainline fix commits for the 3 ported modules — `detect()`
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is version-pinned, not just precondition-only.
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Empirical end-to-end validation on a vulnerable-target VM matrix is
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the next roadmap item; until then, the corpus is best understood as
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"compiles + detects + structurally correct + honest on failure" —
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and the three ported modules have not been run against a vulnerable
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target at all.
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See [`ROADMAP.md`](ROADMAP.md) for the next planned modules and
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infrastructure work.
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## Contributing
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PRs welcome for: kernel offsets (run `--dump-offsets` on a target
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kernel, paste into `core/offsets.c`), new modules, detection rules,
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and CVE-status corrections. See [`CONTRIBUTING.md`](CONTRIBUTING.md).
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**Keeping `kernel_range` tables current.** `tools/refresh-kernel-ranges.py`
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polls Debian's security tracker and reports drift between each
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module's hardcoded `kernel_patched_from` thresholds and the
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fixed-versions Debian actually ships. Run periodically (or in CI)
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to catch new backports that need to land in the corpus:
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```bash
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tools/refresh-kernel-ranges.py # human report
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tools/refresh-kernel-ranges.py --json # machine-readable
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tools/refresh-kernel-ranges.py --patch # proposed C-source edits
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```
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## Acknowledgments
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Each module credits the original CVE reporter and PoC author in its
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`NOTICE.md`. SKELETONKEY is the bundling and bookkeeping layer;
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the research credit belongs to the people who found the bugs.
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## License
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MIT — see [`LICENSE`](LICENSE).
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