Data::Buffer::Shared versions prior to 0.05 create a memory-mapped backing file with permissions 0666 modified by the default umask 022, resulting in a file mode of 0644 (world-readable). The file is opened without the O_NOFOLLOW flag, allowing an attacker to plant a symlink at the file path. Because the shared segment resides in a shared directory accessible by local users, this can lead to unauthorized reading of IPC payloads or redirection of file operations to arbitrary files via symlink attacks. The vulnerability is categorized under CWE-732 (Incorrect Permission Assignment for Critical Resource) and CWE-59 (Improper Link Resolution). No official patch or remediation level has been published yet.

Local users on the system can read sensitive inter-process communication data stored in the world-readable shared memory segment. Additionally, by planting a symlink at the expected file path, an attacker can redirect file operations to arbitrary files, potentially exposing or corrupting data. This compromises confidentiality and integrity of IPC data on affected systems.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to shared directories such as /tmp or /dev/shm to trusted users only and monitor for suspicious symlink creation. Avoid running vulnerable versions in multi-user environments where untrusted users have local access.