leviathan
9d88b475c1
The README has been claiming "each module credits the original CVE
reporter and PoC author in its NOTICE.md" since v0.1.0, but only
copy_fail_family actually shipped one. Fixed.
modules/<name>/NOTICE.md (×19 new + 1 existing): per-module
research credit covering CVE ID, discoverer, original advisory
URL where public, upstream fix commit, IAMROOT's role.
iamroot.c: new --dump-offsets subcommand. Resolves kernel offsets
via the existing core/offsets.c four-source chain (env →
/proc/kallsyms → /boot/System.map → embedded table), then emits
a ready-to-paste C struct entry for kernel_table[]. Run once
as root on a target kernel build; upstream via PR. Eliminates
fabricating offsets — every shipped entry traces back to a
`iamroot --dump-offsets` invocation on a real kernel.
docs/OFFSETS.md: documents the --dump-offsets workflow.
CVES.md: notes the NOTICE.md convention + offset dump tool.
iamroot.c: bump IAMROOT_VERSION 0.3.0 → 0.3.1.
914 B
NOTICE — overlayfs (CVE-2021-3493)
Vulnerability
CVE-2021-3493 — Ubuntu overlayfs userns file-capability injection → host root via setcap'd binaries in a userns-mounted overlay.
Research credit
Reported by Vasily Kulikov, April 2021. Ubuntu-specific because upstream didn't enable unprivileged userns-overlayfs-mount until 5.11.
Advisory: USN-4915-1 / USN-4916-1 (Canonical, April 2021).
Public PoC: vsh-style userns + overlayfs + xattr injection chain.
IAMROOT role
Detect parses /etc/os-release for ID=ubuntu, checks
unprivileged_userns_clone sysctl, and with --active performs the
mount as a fork-isolated probe. The full exploit performs the
userns+overlayfs mount, plants a setcap'd carrier binary in the
upper layer, and execs it from the unprivileged side to obtain root
on the host. Ships auditd rules covering mount(overlay) and
setxattr(security.capability).