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.
26 lines
914 B
Markdown
26 lines
914 B
Markdown
# NOTICE — overlayfs (CVE-2021-3493)
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## Vulnerability
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**CVE-2021-3493** — Ubuntu overlayfs userns file-capability injection
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→ host root via setcap'd binaries in a userns-mounted overlay.
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## Research credit
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Reported by **Vasily Kulikov**, April 2021. Ubuntu-specific because
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upstream didn't enable unprivileged userns-overlayfs-mount until 5.11.
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Advisory: USN-4915-1 / USN-4916-1 (Canonical, April 2021).
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Public PoC: vsh-style userns + overlayfs + xattr injection chain.
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## IAMROOT role
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Detect parses `/etc/os-release` for `ID=ubuntu`, checks
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`unprivileged_userns_clone` sysctl, and with `--active` performs the
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mount as a fork-isolated probe. The full exploit performs the
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userns+overlayfs mount, plants a setcap'd carrier binary in the
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upper layer, and execs it from the unprivileged side to obtain root
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on the host. Ships auditd rules covering `mount(overlay)` and
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`setxattr(security.capability)`.
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