The flaw in Data::ReqRep::Shared prior to version 0.05 causes the module to create a memory‑mapped backing file with permission 0644 under a normal umask of 022, making the file world‑readable. Additionally, the code opens the file with the flags O_RDWR | O_CREAT but without O_EXCL or O_NOFOLLOW. This omission allows a local user to pre‑create a file or place a symbolic link at the target path; the module will follow the link or open the pre‑created file silently. Consequently any local user can read or manipulate the contents of the shared memory segment without authorization, resulting in local data disclosure. The weakness is classified as CWE‑59 (Path Traversal and Directory Traversal) and CWE‑732 (Incorrect Permission Assignment for System Objects).

Data::ReqRep::Shared published by EGOR is the affected product. All versions before 0.05 contain the vulnerability; releases 0.05 and later fix the issue. Deployments utilizing Data::ReqRep::Shared 0.04 or earlier on any system where the module creates its backing file in a world‑accessible directory (e.g., /tmp or /dev/shm) are susceptible.

The CVSS score is 3.8, indicating a low severity, while the EPSS score is less than 1%, suggesting a low probability of exploitation at this time. The vulnerability is not catalogued in CISA KEV. Exploitation requires local user privileges and the ability to write to the shared directory (eg. /tmp or /dev/shm). An attacker who can place a symlink or pre‑create a file can cause the module to read or redirect the shared segment, leading to confidential information disclosure but not to remote code execution or privilege escalation.