In uutils coreutils' mktemp utility, an empty TMPDIR environment variable is improperly handled. Unlike GNU mktemp, which defaults to /tmp when TMPDIR is empty, uutils mktemp uses the empty string as a directory path, resulting in temporary files being created in the current working directory. This can expose temporary files to unauthorized users if the current directory is less secure than /tmp. This issue affects versions of uutils coreutils prior to 0.6.0.

Temporary files intended to be created in a secure temporary directory may instead be created in the current working directory. If this directory is accessible by other users or has weaker permissions, it can lead to unintended information disclosure or unauthorized access to temporary data. The impact is limited to confidentiality and does not affect integrity or availability.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should verify if a fixed version (0.6.0 or later) is available and upgrade accordingly. Until patched, avoid running mktemp with an empty TMPDIR environment variable or ensure the current working directory is secure and not accessible by unauthorized users.