Adds the third ported module — Pack2TheRoot, a userspace PackageKit
D-Bus TOCTOU LPE — and spends real effort hardening --auto so its
detect step gives an accurate, robust verdict before deploying.
pack2theroot (CVE-2026-41651):
- Ported from the public Vozec PoC
(github.com/Vozec/CVE-2026-41651). Original disclosure by the
Deutsche Telekom security team.
- Two back-to-back InstallFiles D-Bus calls (SIMULATE then NONE)
overwrite the cached transaction flags between polkit auth and
dispatch. GLib priority ordering makes the overwrite deterministic,
not a timing race; postinst of the malicious .deb drops a SUID bash
in /tmp.
- detect() reads PackageKit's VersionMajor/Minor/Micro directly over
D-Bus and compares against the pinned fix release 1.3.5 (commit
76cfb675). This is a high-confidence verdict, not precondition-only.
- Debian-family only (PoC builds its own .deb in pure C; ar/ustar/
gzip-stored inline). Cleanup removes /tmp .debs + best-effort
unlinks /tmp/.suid_bash + sudo -n dpkg -r the staging packages.
- Adds an optional GLib/GIO build dependency. The top-level Makefile
autodetects via `pkg-config gio-2.0`; when absent the module
compiles as a stub returning PRECOND_FAIL.
- Embedded auditd + sigma rules cover the file-side footprint
(/tmp/.suid_bash, /tmp/.pk-*.deb, non-root dpkg/apt execve).
--auto accuracy improvements:
- Auto-enables --active before the scan. Per-module sentinel probes
(page-cache /tmp files, fork-isolated namespace mounts) turn
version-only checks into definitive verdicts, so silent distro
backports don't fool the scan and --auto won't pick blind on
TEST_ERROR.
- Per-module verdict printing — every module's result is shown
(VULNERABLE / patched / precondition / indeterminate), not just
VULNERABLE rows. Operator sees the full picture.
- Scan-end summary line: "N vulnerable, M patched/n.a., K
precondition-fail, L indeterminate" with a separate callout when
modules crashed.
- Distro fingerprint added to the auto banner (ID + VERSION_ID from
/etc/os-release alongside kernel/arch).
- Fork-isolated detect() — each detector runs in a child process so
a SIGILL/SIGSEGV in one module's probe is contained and the scan
continues. Surfaced live while testing: entrybleed's prefetchnta
KASLR sweep SIGILLs on emulated CPUs (linuxkit on darwin); without
isolation the whole --auto died at module 7 of 31. With isolation
the scan reports "detect() crashed (signal 4) — continuing" and
finishes cleanly.
module_safety_rank additions:
- pack2theroot: 95 (userspace D-Bus TOCTOU; dpkg + /tmp SUID footprint
— clean but heavier than pwnkit's gconv-modules-only path).
- dirtydecrypt / fragnesia: 86 (page-cache writes; one step below the
verified copy_fail/dirty_frag family at 88 to prefer verified
modules when both apply).
Docs:
- README badge / tagline / tier table / ⚪ block / example output /
v0.5.0 status — all updated to "28 verified + 3 ported".
- CVES.md counts line, the ported-modules note (now calling out
pack2theroot's high-confidence detect vs. precondition-only for
the page-cache pair), inventory row, operations table row.
- ROADMAP Phase 7+: pack2theroot moved out of carry-overs into the
"landed (ported, pending VM verification)" group; added a new
"--auto accuracy work" subsection documenting the dispatcher
hardening landed in this commit.
- docs/index.html: scanning-count example bumped to 31, status line
updated to mention 3 ported modules.
Build verification: full `make clean && make` in `docker gcc:latest`
with libglib2.0-dev installed: links into a 31-module skeletonkey
ELF (413KB), `--list` shows all modules including pack2theroot,
`--detect-rules --format=auditd` emits the new pack2theroot section,
`--auto --i-know --no-shell` exercises the new banner + active
probes + verdict table + fork isolation + scan summary end-to-end.
Only build warning is the pre-existing
`-Wunterminated-string-initialization` in dirty_pipe (not introduced
here).
Two new page-cache-write LPE modules, both ported from the public V12
security PoCs (github.com/v12-security/pocs):
- dirtydecrypt (CVE-2026-31635): rxgk missing-COW in-place decrypt.
rxgk_decrypt_skb() decrypts spliced page-cache pages before the HMAC
check, corrupting the page cache of a read-only file. Sibling of
Copy Fail / Dirty Frag in the rxrpc subsystem.
- fragnesia (CVE-2026-46300): XFRM ESP-in-TCP skb_try_coalesce() loses
the SHARED_FRAG marker, so the ESP-in-TCP receive path decrypts
page-cache pages in place. A latent bug exposed by the Dirty Frag
fix (f4c50a4034e6). Retires the old _stubs/fragnesia_TBD stub.
Both wrap the PoC exploit primitive in the skeletonkey_module
interface: detect/exploit/cleanup, an --active /tmp sentinel probe,
--no-shell support, and embedded auditd + sigma rules. The exploit
body runs in a forked child so the PoC's exit()/die() paths cannot
tear down the dispatcher. The fragnesia port drops the upstream PoC's
ANSI TUI (incompatible with a shared dispatcher); the exploit
mechanism is reproduced faithfully. Linux-only code is guarded with
#ifdef __linux__ so the modules still compile on non-Linux dev boxes.
VERIFICATION: ported, NOT yet validated end-to-end on a
vulnerable-kernel VM. The CVE fix commits are not pinned, so detect()
is precondition-only (PRECOND_FAIL / TEST_ERROR, never a blind
VULNERABLE) and --auto will not fire them unless --active confirms.
macOS stub-path compiles verified locally; the Linux exploit-path
build is covered by CI (build.yml, ubuntu) only. See each MODULE.md.
Wiring: core/registry.h, skeletonkey.c, Makefile, CVES.md, ROADMAP.md.
Pre-scaffolding for the next batch (CVE-2023-32233, CVE-2023-4622,
CVE-2022-25636, CVE-2023-0179). Each module ships as a 21-line
stub returning PRECOND_FAIL; parallel agents fill in the real
detect/exploit/--full-chain implementations.
This commit keeps registry.h / iamroot.c / Makefile in one place
so the 4 parallel agents don't collide on shared-file edits — they
each own a single iamroot_modules.c.
Build clean on Debian 6.12.86; --list shows all 24 modules
including the 4 new stubs.
Adds the infrastructure the 7 🟡 PRIMITIVE modules can wire into for
full-chain root pops.
core/offsets.{c,h}: four-source kernel-symbol resolution chain
1. env vars (IAMROOT_MODPROBE_PATH, IAMROOT_INIT_TASK, …)
2. /proc/kallsyms (only useful when kptr_restrict=0 or root)
3. /boot/System.map-$(uname -r) (world-readable on some distros)
4. embedded table keyed by uname-r glob (entries are
relative-to-_text, applied on top of an EntryBleed kbase leak;
seeded empty in v0.2.0 — schema-only — to honor the
no-fabricated-offsets rule).
core/finisher.{c,h}: shared root-pop helpers given a module's
arb-write primitive.
Pattern A (modprobe_path):
write payload script /tmp/iamroot-mp-<pid>.sh, arb-write
modprobe_path ← that path, execve unknown-format trigger,
wait for /tmp/iamroot-pwn-<pid> sentinel + setuid bash copy,
spawn root shell.
Pattern B (cred uid): stub — needs arb-READ too; modules use
Pattern A unless they have read+write.
On offset-resolution failure: prints a verbose how-to-populate
diagnostic and returns EXPLOIT_FAIL honestly.
core/module.h: + bool full_chain in iamroot_ctx
iamroot.c: + --full-chain flag (longopt 7, sets ctx.full_chain)
+ help text describing primitive-only-by-default + the
opt-in to attempt the full chain.
Makefile: add core/offsets.o + core/finisher.o to CORE_SRCS.
Build clean on Debian 6.12.86; --help renders the new flag.
10th module. Ubuntu-specific userns + overlayfs LPE that injects file
capabilities cross-namespace.
- modules/overlayfs_cve_2021_3493/iamroot_modules.{c,h}:
- is_ubuntu() — parses /etc/os-release for ID=ubuntu or
ID_LIKE=ubuntu. Non-Ubuntu hosts get IAMROOT_OK immediately (the
bug is specific to Ubuntu's modified overlayfs).
- unprivileged_userns_clone gate — sysctl=0 → PRECOND_FAIL
- Active probe (--active): forks a child that enters userns +
mountns and attempts the overlayfs mount inside /tmp. Mount
success on Ubuntu = VULNERABLE. Mount denied = patched / AppArmor
block. Child-isolated so parent's namespace state is untouched.
- Version fallback: kernel < 5.13 = vulnerable-by-inference for
Ubuntu kernels; recommend --active for confirmation.
- Exploit: detect-only stub. Reference vsh's exploit-cve-2021-3493
for full version (mount overlayfs in userns, drop binary with
cap_setuid+ep into upper layer, re-exec outside ns).
- Embedded auditd rules: mount(overlay) syscall + security.capability
xattr writes (the exploit's two-step footprint).
Verified end-to-end on kctf-mgr (Debian):
iamroot --scan → 'not Ubuntu — bug is Ubuntu-specific' → IAMROOT_OK
Module count: 10. Active-probe pattern now applies to dirty_pipe,
entrybleed, and overlayfs (and copy_fail_family via existing
dirtyfail_active_probes global). Detect quality across the corpus
materially improved this session.
dirty_pipe detect: active sentinel probe (Phase 1.5-ish improvement)
- New dirty_pipe_active_probe(): creates a /tmp probe file with known
sentinel bytes, fires the Dirty Pipe primitive against it, re-reads
via the page cache, returns true if the poisoning landed.
- detect() gated on ctx->active_probe: --scan does version-only check
(fast, no side effects); --scan --active fires the empirical probe
and overrides version inference with the empirical verdict. Catches
silent distro backports that don't bump uname() version.
- Three verdicts now distinguishable:
(a) version says patched, no active probe → 'patched (version-only)'
(b) version says vulnerable, --active fires + probe lands → CONFIRMED
(c) version says vulnerable, --active fires + probe blocked → 'likely
patched via distro backport'
- Probe is safe: only /tmp, no /etc/passwd.
nf_tables CVE-2024-1086 (detect-only, new module):
- Famous Notselwyn UAF in nft_verdict_init. Affects 5.14 ≤ K, fixed
mainline 6.8 with backports landing in 5.4.269 / 5.10.210 / 5.15.149
/ 6.1.74 / 6.6.13 / 6.7.2.
- detect() checks: kernel version range, AND unprivileged user_ns clone
availability (the exploit's reachability gate — kernel-vulnerable
but userns-locked-down hosts report PRECOND_FAIL, signalling that
the kernel still needs patching but unprivileged path is closed).
- Ships auditd + sigma detection rules: unshare(CLONE_NEWUSER) chained
with setresuid(0,0,0) on a previously-non-root process is the
exploit's canonical telltale.
- Full Notselwyn-style exploit (cross-cache UAF → arbitrary R/W → cred
overwrite or modprobe_path hijack) is the next commit.
9 modules total now. CVES.md and ROADMAP.md updated.
- modules/entrybleed_cve_2023_0458/ (promoted out of _stubs):
- iamroot_modules.{c,h}: full EntryBleed primitive (rdtsc_start/end
+ prefetchnta + KASLR-slot timing sweep) wired into the standard
iamroot_module interface. x86_64 only; ARM/other gracefully
return IAMROOT_PRECOND_FAIL.
- detect(): reads /sys/.../vulnerabilities/meltdown to decide
KPTI status. Mitigation: PTI → VULNERABLE. Not affected → OK.
- exploit(): sweeps the 16MiB KASLR range, prints leaked kbase
(and KASLR slide). JSON-mode emits {"kbase":"0x..."} to stdout.
- entrybleed_leak_kbase_lib(off) declared as a public library
helper so future LPE chains needing a stage-1 leak can just
#include the module's header and call it.
- entry_SYSCALL_64 slot offset overridable via
IAMROOT_ENTRYBLEED_OFFSET (default 0x5600000 for lts-6.12.x).
- __always_inline fallback added since glibc/Linux-kernel macro
isn't universal; module now builds clean under macOS clangd lint
and on musl.
- iamroot.c registers entrybleed alongside the other families;
Makefile gains it as a separate object set.
Verified end-to-end on kctf-mgr (Debian 6.12.86):
iamroot --exploit entrybleed --i-know
→ [+] entrybleed: leaked kbase = 0xffffffff8d800000
This is the FIRST WORKING-EXPLOIT module in IAMROOT (5
copy_fail_family modules wrap existing code from DIRTYFAIL;
dirty_pipe is detect-only). EntryBleed is x86_64 stage-1 brick
that future chains can compose.
- core/kernel_range.{c,h}: branch-aware patched-version comparison.
Every future module needs 'is the host kernel in the affected
range?'; centralized here. Models stable-branch backports
(e.g. 5.10.102, 5.15.25) so a 5.15.20 host correctly reports
VULNERABLE while a 5.15.50 host reports OK.
- modules/dirty_pipe_cve_2022_0847/ (promoted out of _stubs):
- iamroot_modules.{c,h}: dirty_pipe module exposing detect() that
parses /proc/version and compares against the four known patched
branches (5.10.102, 5.15.25, 5.16.11, 5.17+ inherited). Returns
IAMROOT_OK / IAMROOT_VULNERABLE / IAMROOT_TEST_ERROR with stderr
hints in human-readable scan mode.
- exploit() returns IAMROOT_PRECOND_FAIL with a 'not yet
implemented' message; landing the actual exploit needs Phase 1.5
extraction of passwd/su helpers into core/.
- detect/auditd.rules: splice() syscall + passwd/shadow file watches
- detect/sigma.yml: non-root modification of /etc/passwd|shadow|sudoers
- iamroot.c main() calls iamroot_register_dirty_pipe() alongside
the copy_fail_family registration.
- Makefile gains the dirty_pipe family as a separate object set.
Verified end-to-end on kctf-mgr (kernel 6.12.86): build clean, 6
modules in --list, --scan correctly reports dirty_pipe as patched,
JSON output ingest-ready.