pterodactyl/wings · Security
Pterodactyl Wings: Chmod operation can be used to change permissions of files outside of the server container
- GHSA ID
- GHSA-rhq6-9rgh-v45c
- Severity
- medium
- Published
- Updated
- CVSS
- 5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
- CVSS v3
- 5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
Description
In wings/internal/ufs/fs_unix.go (line 92-94), this function is defined and is used to change permissions of files in the server:
func (fs *UnixFS) fchmodat(op string, dirfd int, name string, mode FileMode) error {
return ensurePathError(unix.Fchmodat(dirfd, name, uint32(mode), 0), op, name)
}
This call to the unix function fchmodat(int fd, char* name, mode_t mode, int flags) does not have the flag AT_SYMLINK_NOFOLLOW set, and Wings neither checks or validate if the target file is a symlink. This allows one to change permissions of files or folders outside of the server container by making symlinks to existing files in the host and then chmoding it.