Data

Data::RoaringBitmap::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 roaring.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: 2026-07-21T19:08:49.522Z
Updated: 2026-07-27T14:07:43.749Z

Data::RoaringBitmap::Shared versions before 0.02 for Perl allow an out-of-bounds read via an unvalidated container offset and cardinality in rb_contains_locked. The attach-time validator rb_validate_header checks the header scalars and region layout against the file size, but does not validate the bucket contents it then trusts. rb_contains_locked forms a container pointer as pool + container_off * 8192 from a raw file-stored offset and then searches over a file-stored cardinality, neither bounded against the container pool capacity or the fixed 8192-byte slot size. A local peer that can write the backing file can leave the header valid while poisoning a bucket, so the next membership query dereferences a file-controlled wild pointer and scans a file-controlled count, reading adjacent memory or crashing the process.

Published: 2026-07-21T19:04:04.057Z
Updated: 2026-07-23T12:14:48.600Z