Hash: SHA256

             AUSCERT External Security Bulletin Redistribution

                     USN-4424-1: snapd vulnerabilities
                               16 July 2020


        AusCERT Security Bulletin Summary

Product:           snapd
Publisher:         Ubuntu
Operating System:  Ubuntu
                   Linux variants
Impact/Access:     Reduced Security    -- Unknown/Unspecified
                   Unauthorised Access -- Console/Physical   
Resolution:        Patch/Upgrade
CVE Names:         CVE-2020-11934 CVE-2020-11933 

Original Bulletin: 

Comment: This advisory references vulnerabilities in products which run on 
         platforms other than Ubuntu. It is recommended that administrators 
         running snapd check for an updated version of the software for their
         operating system.

- --------------------------BEGIN INCLUDED TEXT--------------------

USN-4424-1: snapd vulnerabilities
15 July 2020

snapd vulnerabilities

  o Ubuntu 20.04 LTS
  o Ubuntu 19.10
  o Ubuntu 18.04 LTS
  o Ubuntu 16.04 LTS


  o snapd - Daemon and tooling that enable snap packages


It was discovered that cloud-init as managed by snapd on Ubuntu Core 16 and
Ubuntu Core 18 devices ran on every boot without restrictions. A physical
attacker could exploit this to craft cloud-init user-data/meta-data via
external media to perform arbitrary changes on the device to bypass
intended security mechanisms such as full disk encryption. This issue did
not affect traditional Ubuntu systems. (CVE-2020-11933)

It was discovered that snapctl user-open allowed altering the XDG_DATA_DIRS
environment variable when calling the system xdg-open. A malicious snap
could exploit this to bypass intended access restrictions to control how
the host system xdg-open script opens the URL. This issue did not affect
Ubuntu Core systems. (CVE-2020-11934)

Update instructions

The problem can be corrected by updating your system to the following package

Ubuntu 20.04

  o snapd - 2.45.1+20.04.2

Ubuntu 19.10

  o snapd - 2.45.1+19.10.2

Ubuntu 18.04

  o snapd - 2.45.1+18.04.2

Ubuntu 16.04

  o snapd - 2.45.1ubuntu0.2

In general, a standard system update will make all the necessary changes.
On Ubuntu, snapd will automatically refresh itself to snapd 2.45.2 which
is unaffected.


  o CVE-2020-11933
  o CVE-2020-11934

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


Australian Computer Emergency Response Team
The University of Queensland
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
Comment: http://www.auscert.org.au/render.html?it=1967