[OpenWrt-Devel] Test results of OpenWrt 15.05.1 according to BSI test concept for home routers

Eric Schultz eschultz at prplfoundation.org
Wed Apr 26 16:23:23 EDT 2017

On 04/08/2017 11:38 AM, Hauke Mehrtens wrote:

> The German Bundesamt für Sicherheit in der Informationstechnik (short:
> BSI, English: Federal Office for Information Security) published a
> "Testkonzept für Breitband-Router (DSL-, Kabel-, SOHO-, CE-, CPE-Router,
> IADs)" (English: Test concept for broadband routers). This test concept
> is only available in German and most chapters are published in the
> public by the BSI, chapter 4 and 5 are only available after signing a
> NDA (Traffic Light Protocol) with the BSI:
> https://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/Cyber-Sicherheit/Themen/Testkonzept-Breitbandrouter.pdf?__blob=publicationFile&v=5
> Some unnamed organization tested OpenWrt 15.05.1 on a TP-Link  TL-WR841N
> V10.0 according to this test concept. Because I commented on the first
> public draft of the test concept and said that I am active in the
> OpenWrt project, the organization contacted me to check if their test
> results are correct and provided me with the full test report under NDA.
> OpenWrt 15.05.1 failed this test and LEDE will probably also fail this
> test, because we failed on section 4.5.1 "Firewall-Bypass", which is a
> criterion for exclusion (Ausschlusskriterium), see details below.
> The test concept focus on "normal" routers and only tests the web GUI
> and also looks mostly on features normal home routers have. We are
> missing some functionality like individual default password, for the web
> GUI and the Wifi, the logging is not very good and so on. The tests
> regarding DNS are interesting and more advanced, if someone wants to
> look into that it would be very nice.
> The main problem is in section 4.5.1 "Firewall-Bypass".
> OpenWrt and LEDE implement RFC4890 section 4.3.1:
> -------------------------------------------------------------------
> 4.3.1.  Traffic That Must Not Be Dropped
>    Error messages that are essential to the establishment and
>    maintenance of communications:
>    o  Destination Unreachable (Type 1) - All codes
>    o  Packet Too Big (Type 2)
>    o  Time Exceeded (Type 3) - Code 0 only
>    o  Parameter Problem (Type 4) - Codes 1 and 2 only
>    Appendix A.4 suggests some more specific checks that could be
>    performed on Parameter Problem messages if a firewall has the
>    necessary packet inspection capabilities.
>    Connectivity checking messages:
>    o  Echo Request (Type 128)
>    o  Echo Response (Type 129)
> -------------------------------------------------------------------
> The BSI used RFC6092 (Recommended Simple Security Capabilities in
> Customer Premises Equipment (CPE) for Providing Residential IPv6
> Internet Service) with this section as the base for the test:
> -------------------------------------------------------------------
> 3.2.1.  Internet Control and Management
>    Recommendations for filtering ICMPv6 messages in firewall devices are
>    described separately in [RFC4890] and apply to residential gateways,
>    with the additional recommendation that incoming "Destination
>    Unreachable" and "Packet Too Big" error messages that don't match any
>    filtering state should be dropped.
>    REC-10: IPv6 gateways SHOULD NOT forward ICMPv6 "Destination
>    Unreachable" and "Packet Too Big" messages containing IP headers that
>    do not match generic upper-layer transport state records.
> -------------------------------------------------------------------
> Attached are the results of this test of OpenWrt 15.05.1. The
> information on how the tests from chapter 4 and 5 are done is redacted
> from the document, if you want to work on these problems and would like
> to get more details about the problems from chapter 4 and 5, please
> contact me. I can also help you with translating the problem from German
> to English. ;-)
> The "sensitive" informations are under the Traffic Light Protocol
> classification "TLP AMBER", see these German information about the NDA:
> https://mip.bsi.bund.de/Anlage_1_TLP-Merkblatt.pdf
> I commented on the tests itself, because they are missing many important
> stuff to test, most of the security problem of IoT devices and home
> routers one hears about in the media are not covered here at all.
> History:
> 20.10.2015: I read this article https://heise.de/-2851354 and wrote some
> comments to the BSI based on the first public draft. In this mail I
> mentioned that I am activate in the OpenWrt project.
> 23.10.2015: The BSI answered me and offered me the full draft when I
> would sign an NDA, I did so and got the full document, but did not
> comment on it again.
> 23.2.2016: I got the full final draft from the BSI
> 22.11.2016: I was told by the unnamed organization that they tested a
> TP-Link device running OpenWrt 15.05.1 and if I could comment on their
> results. I got the results under the NDA and commented in them.
> 31.3.2017: I asked if I can publish at lest some parts of the results
> again and got the OK that I am allowed to publish the redacted results.
> Hauke
> _______________________________________________
> openwrt-devel mailing list
> openwrt-devel at lists.openwrt.org
> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel


A few members of prpl have expressed interest in organizing a public
group to evaluate the results of this document and see what can be
learned from it for OpenWrt/LEDE, with a particular focus on security.
I'm sure there are others here who are interested in the same topic.

Is there a specific group already dedicated to addressing this? If so,
please let me know and I'll let the prpl members know.

If not, I'd like to organize or work with others to organize such a
group.If you have particular interest in this topic, please let me know
if you'd like to participate in or help organize this group.

Thanks all,

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