We believe that your issue has been closed by the upload of
Version 0.26.7 of grml-live from Michael Prokop <mika@grml.org>.
The explanation is attached below

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Format: 1.8
Date: Sat, 06 Jun 2015 01:41:40 +0200
Source: grml-live
Binary: grml-live grml-live-db
Architecture: source all
Version: 0.26.7
Distribution: unstable
Urgency: medium
Maintainer: Michael Prokop <mika@grml.org>
Changed-By: Michael Prokop <mika@grml.org>
Description:
 grml-live  - build system for creating a Grml (based) Linux live system
 grml-live-db - log package build information of grml-live to database
Changes:
 grml-live (0.26.7) unstable; urgency=medium
 .
   * Software related changes:
     - [46560db] add uml-utilities to GRML_FULL [Closes: issue1344]
     - [ed11f13] add bats to GRML_FULL
   * [ddc3eda] New script 94-update-smart-drivedb to update smartmontools'
     drive database
   * [1f91be9] 94-update-smart-drivedb: do not fail on update-smart-drivedb
     errors
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 aa96333ca76eba124d740eb838a56d8280c49628 68870 grml-live-db_0.26.7_all.deb
 529e279105050e342166d28d4c7da5b78b3d2d5d 496366 grml-live_0.26.7_all.deb
Checksums-Sha256:
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Files:
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 edca6d94b57c491afa09a9b84041225d 68870 grml extra grml-live-db_0.26.7_all.deb
 c2614f116ef4133f294f9161a1bc119b 496366 grml extra grml-live_0.26.7_all.deb

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This is fixed in Git:

 http://git.grml.org/?p=grml-live.git;a=commit;h=46560db16995ef037281ff6076cf2bf0b8b0fc9e

The daily ISOs as of tomorrow should include um-utilities already.

regards,
-mika-

The command tunctl provides a convenient way to create tap devices used by UML 
to to access network.