Hi!

This daemon runs as user nobody, while creating multiple files on the
filesystem owned by the same user, which are used as part of its
security protection. This is a security issue, given that other
daemons on the system might be running as the same user, and worse
when dlt-daemon is writing and parsing files from hardcoded paths
under /tmp.

From base-passwd/users-and-groups.txt.gz:

  ,---
    nobody, nogroup
          Daemons that need not own any files sometimes run as
          user nobody and group nogroup, although using a
          dedicated user is far preferable. Thus, no files on a
          system should be owned by this user or group.

          (Technically speaking, it does no harm for a file to be
          owned by group nogroup as long as the ownership confers
          no additional privileges, that is if the group and other
          permission bits are equal. However, this is sloppy
          practice and should be avoided.)

          If root-squashing is in use over NFS, root access from
          the client is performed as user nobody on the server.
  `---

If you are going to fix this by using a dedicated user/group, please
make sure to namespace them with «_» to distinguish them as system
users and avoid unnecessary collisions with non-system, users. (Such
as _dlt or similar.)

[ The version I used is the earliest I found with the same issue from
  the tracker.d.o page, earlier version might be affected too, dunno. ]

Thanks,
Guillem

We believe that the bug you reported is fixed in the latest version of
dlt-daemon, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1055580@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Gianfranco Costamagna <locutusofborg@debian.org> (supplier of updated dlt-daemon package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Tue, 21 Nov 2023 13:18:22 +0100
Source: dlt-daemon
Built-For-Profiles: noudeb
Architecture: source
Version: 2.18.10-8
Distribution: unstable
Urgency: medium
Maintainer: Aigars Mahinovs <aigarius@debian.org>
Changed-By: Gianfranco Costamagna <locutusofborg@debian.org>
Closes: 1055580
Changes:
 dlt-daemon (2.18.10-8) unstable; urgency=medium
 .
   * Make sure dlt runs as _dlt user, not as nobody (Closes: #1055580)
   * Start using upstream service files.
   * Enable systemd watchdog
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