CVE-2026-65067: CWE-732 Incorrect Permission Assignment for Critical Resource in EGOR Data::Intern::Shared
Data::Intern::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 intern.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.
AI Analysis
Technical Summary
The vulnerability in Data::Intern::Shared (versions before 0.02) arises from creating a mmap backing file with mode 0666, which under typical umask results in a world-readable file (0644). The file is opened without O_EXCL or O_NOFOLLOW flags, allowing an attacker to plant a symlink or pre-existing file at the target path. This leads to incorrect permission assignment (CWE-732) and symlink following (CWE-59), enabling local attackers to read IPC data or win pre-creation races by redirecting the open operation to attacker-controlled files in shared directories.
Potential Impact
Local attackers can read sensitive inter-process communication data stored in the mmap segment due to world-readable permissions. They can also exploit the absence of O_EXCL and O_NOFOLLOW to perform symlink attacks or pre-creation race conditions, potentially redirecting file operations to attacker-controlled files. This compromises confidentiality and integrity of IPC data on affected systems.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid running Data::Intern::Shared versions before 0.02 in environments where untrusted local users have access to shared directories like /tmp or /dev/shm. Consider restricting permissions on these directories or using alternative IPC mechanisms that enforce stricter file permissions and open flags.
CVE-2026-65067: CWE-732 Incorrect Permission Assignment for Critical Resource in EGOR Data::Intern::Shared
Description
Data::Intern::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 intern.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.
Affected software
pkg:github/Data-Intern-SharedRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Data::Intern::Shared (versions before 0.02) arises from creating a mmap backing file with mode 0666, which under typical umask results in a world-readable file (0644). The file is opened without O_EXCL or O_NOFOLLOW flags, allowing an attacker to plant a symlink or pre-existing file at the target path. This leads to incorrect permission assignment (CWE-732) and symlink following (CWE-59), enabling local attackers to read IPC data or win pre-creation races by redirecting the open operation to attacker-controlled files in shared directories.
Potential Impact
Local attackers can read sensitive inter-process communication data stored in the mmap segment due to world-readable permissions. They can also exploit the absence of O_EXCL and O_NOFOLLOW to perform symlink attacks or pre-creation race conditions, potentially redirecting file operations to attacker-controlled files. This compromises confidentiality and integrity of IPC data on affected systems.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid running Data::Intern::Shared versions before 0.02 in environments where untrusted local users have access to shared directories like /tmp or /dev/shm. Consider restricting permissions on these directories or using alternative IPC mechanisms that enforce stricter file permissions and open flags.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- CPANSec
- Date Reserved
- 2026-07-21T15:29:37.116Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a5fcbb92a4a8d5989ac73cd
Added to database: 07/21/2026, 19:42:49 UTC
Last enriched: 07/21/2026, 19:51:43 UTC
Last updated: 07/21/2026, 20:43:07 UTC
Views: 5
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