users may append `root` to group listings

Affected versions append root to group listings, unless the correct listing has exactly 1024 groups.

This affects both:

• The supplementary groups of a user
• The group access list of the current process

If the caller uses this information for access control, this may lead to privilege escalation.

This crate is not currently maintained, so a patched version is not available.

Versions older than 0.8.0 do not contain the affected functions, so downgrading to them is a workaround.

Recommended alternatives

• uzers (an actively maintained fork of the users crate)
• sysinfo