Data::Buffer::Shared prior to version 0.05 creates a memory‑ the common umask 022 becomes 0644, allowing any local user to read the file. The file is opened without the O_NOFOLLOW flag, so a malicious user can replace the file path with a symbolic link to another file. The result is that a local attacker can read or manipulate the data stored in the shared segment or redirect the program to open sensitive files, leading to information disclosure or potential privilege escalation. The weakness is represented by CWE‑59 (Use of Potentially Dangerous Functions) and CWE‑732 (Incorrect Permission Assignment for Critical Resource).

Vulnerable products include EGOR Data::Buffer::Shared, specifically all releases before 0.05. Any deployment that relies on this module and stores its backing file in a shared or /dev/shm is affected. No additional vendor or product details are listed beyond the module name.

The vulnerability has a CVSS score of 6.2, indicating a moderate severity. The EPSS score is less than 1%, suggesting exploitation is unlikely but still possible in targeted or high‑risk environments. It is not listed in the CISA KEV catalog. The most probable attack vector is local: a user who can write to the backing‑file directory and create or modify a symlink can read the contents of the backing file or redirect access to other files. Exploitation requires no special network access and can be performed by a local attacker with permission to write to the shared location.