Description (CNA)
Data::Buffer::Shared versions before 0.05 for Perl create a world-readable mmap backing file and open it without O_NOFOLLOW. The segment is created in buf_generic.h with open(path, O_RDWR|O_CREAT|O_EXCL, 0666). O_EXCL blocks a pre-seeded file on create, but the mode is 0666, so under the default umask 022 the file is created mode 0644 (world-readable), and O_NOFOLLOW is absent, so a symlink planted at the path is followed when the segment is attached. 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 symlink at the path redirects the open to another file.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| EGOR / Data::Buffer::Shared | affected 0 before 0.05 |
CWE
CWE-732, CWE-59
References
- https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/diff/EGOR/Data-Buffer-Shared-0.04#buf_generic.h
- https://metacpan.org/release/EGOR/Data-Buffer-Shared-0.05/changes
ADP enrichment
No English description supplied.
No references supplied.