GHSA-gwm6-q8ch-hcfr

install -D: symlink race in directory creation allows arbitrary file overwrite

The `-D` path runs `fs::create_dir_all` on a pathname then later opens the destination via path-based `File::create`/`fs::copy`, neither anchored to a directory fd. Between the two, an attacker can replace a path component with a symlink, redirecting the write. **Impact:** an attacker with concurrent write access to the destination tree can redirect a privileged `install -D` to an arbitrary location, enabling arbitrary file overwrite with attacker-controlled content. Recommendation: use dirfd-based traversal (`openat`/`mkdirat` + `O_NOFOLLOW`) per component and create the destination via `openat` on the same dirfd. **Remediation:** Acknowledged by Canonical; fixed in commit 0c412999. --- _Reported by Zellic in the *uutils coreutils Program Security Assessment* (prepared for Canonical, Jan 20 2026), audited commit `3a07ffc5a9bd4c283e75afa548ba1f1957bad242`. Finding 3.51. Credit: Zellic._