- Block bash's history builtin when it reads/writes a file (history -w / -a / -r / -n): it can
create or overwrite an arbitrary host path (or read a file into the buffer) in the unguarded
shell child. Bare history / -c / -d / -p / -s stay allowed.
- Combine a subprocess cwd= with relative argv paths in the sensitive-read scan, so
subprocess.run(['cat', 'passwd'], cwd='/etc') is seen as a /etc/passwd read.
- Track env -C DIR / --chdir DIR in the shell-string read scan so a later relative reader
argument (env -C /etc cat passwd) resolves against DIR.
- Record aliases created by tuple/list unpacking assignments ((s,) = (os.system,); a, b =
os.system, 1; [e] = [exec]) in the scope alias index, pairing a literal target with a literal
RHS element-wise, so the shell/exec/deserializer sink checks see them.
- Pin the builtins the runtime path guard consults (isinstance / int / bytes / str / any) into
the guard namespace, so sandboxed code cannot reassign builtins.isinstance to make
isinstance(path, int) treat an outside path as an fd and approve an absolute write.
- Re-pin os.path.stat + S_ISLNK before each realpath resolution in the guard, so a
os.path.stat.S_ISLNK = lambda mode: False (stopping realpath from following an in-workdir
symlink that escapes) cannot approve a write the real open() then routes outside.
- Restore the /root/ protection in the runtime sensitive-read backstop for an opaque path,
carving out package / library trees (site-packages, dist-packages, the stdlib) so imports
under a root home are not broken.
Adds TestRound26Bypasses plus runtime tests for the pinned builtins / stat and root-home reads.
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