GHSA-6xx4-9wp6-65p7: skilo add follows symbolic links, allowing arbitrary local file disclosure from a malicious skill source

skilo add installs a skill by recursively copying the skill directory into the target skills directory. The copy routine (copy_dir_all) classified each entry with std::fs::DirEntry::file_type() — which does not follow symlinks — and then copied non-directory entries with std::fs::copy(), which does dereference symlinks.

As a result, a skill containing a symbolic link such as reference.txt -> /home/<user>/.ssh/id_rsa was copied as a regular file whose contents are the link’s target. A malicious skill source — for example a git repository installed via skilo add github.com/<attacker>/<skills>, or a local path — could read arbitrary files readable by the user running skilo add (SSH keys, cloud credentials, .env files, etc.) and place their contents inside the installed skill directory, where the user or their agent may later read, share, or sync them.

This is arbitrary local file disclosure (CWE-59 / CWE-61, symlink following) triggered by installing an untrusted skills source.