Data

Data::SpatialHash::Shared versions before 0.02 for Perl create a world-readable mmap backing file and open it without O_EXCL or O_NOFOLLOW. The segment is created in sphash.h with open(path, O_RDWR|O_CREAT, 0666). The mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable). O_NOFOLLOW is absent, so a symlink planted at the path is followed, and O_EXCL is absent, so the open silently uses a pre-planted file instead of failing. A "Shared" segment naturally lives in a shared directory such as /tmp or /dev/shm, where any local user can read the IPC payloads stored in the world-readable segment, and a pre-planted file or symlink at the path lets a local attacker win a pre-creation race or redirect the open.

Published: 2026-07-21T19:09:41.280Z
Updated: 2026-07-23T13:18:33.180Z

Data::SpatialHash::Shared versions before 0.02 for Perl allow out-of-bounds reads and writes via unvalidated bucket, link and free-list indices in sph_walk_cell and sph_alloc_slot. The attach-time validator sph_validate_header checks the header scalars and region layout against the file size, but does not validate the array contents it then trusts. sph_walk_cell reads entries[buckets[b]] and follows each entry's next link raw, and sph_alloc_slot writes through a file-stored free_head index, none bounded against the entry count (max_entries). A local peer that can write the backing file can leave the header valid while poisoning the bucket chain and free list, so a query reads through an out-of-bounds bucket and next index and an insert writes through an out-of-bounds free-list head, corrupting memory or crashing the process.

Published: 2026-07-21T19:04:56.729Z
Updated: 2026-07-22T19:36:54.589Z