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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Internet’ Category

Urgent security advisory – MikroTik – upgrade to 6.41.3 if you can change your bridge implementation, ensure SMB and WWW are not WAN accessible

Posted by jpluimers on 2018/03/31

I both understand the [WayBack] Urgent security advisory – MikroTik and the users reluctant to upgrade: Mikrotik has a history of updates breaking existing behaviour and underdocumenting features and release notes.

The attack is over the www or www-ssl services which by default run on port 80 and 443. You can see on which networks they are bound using this example from the terminal:

> ip service print where name=www
Flags: X - disabled, I - invalid 
 #   NAME       PORT ADDRESS                                        CERTIFICATE   
 0   www          80 192.168.71.0/24                               
                     192.168.171.0/24                              
                     192.168.124.0/24
> ip service print where name=www-ssl
Flags: X - disabled, I - invalid 
 #   NAME       PORT ADDRESS                                        CERTIFICATE   
 0   www-ssl     443 192.168.71.0/24                               
                     192.168.171.0/24                              
                     192.168.124.0/24

Note that if your device was infected, not all upgrades will remove the infection on all machines (even though it is mentioned in the FAQ below!). This is one of the “underdocumenting” aspects I mentioned.

There is no way to officially check if your device is infected. If you suspect it is and cannot upgrade to 6.41.3 or more recent, then you need to use [WayBack] Manual:Netinstall – MikroTik Wiki to wipe clean your router and re-install.

Be careful which version you upgrade to:

Somewhere in the middle of page 2 of the above post [WayBack], this is slightly addressed:

1) Upgrade to 6.38.5 fixes the botnet scanner and removes it.
2) Upgrade to 6.41.3 fixes SMB vulnerability.

Later this morning further below on page 2 of the above post [WayBack] it was elaborated more:

I recommend that you re-read all the posts from “normis”. Seems that we are going into circles.

1) Winbox port is used only to find out that this is RouterOS powered device (Winbox is not affected by vulnerabilities that we know of);
2) WWW service (“/ip service”) is used in order to “hack” your router if Firewall did not drop connections to this port (affected service was Webfig which by default is running on port 80, but you can change port under “/ip service” menu and then this other port must be protected). For example, “/ip firewall filter add chain=input action=drop in-interface=WAN connection-state=new”;
3) Issue with SMB is completely another thing but the same rules apply. If device (in this case SMB port) is protected by firewall, then no one can use this issue in order to mess up with your router. Usually attacks come to your router from public Internet (not from LAN) and in normal situation SMB access is not open for public Internet;
4) There is not and will not be an official way to gain access to routers shell.

You will be safe from both of these issues if you upgrade your routers (6.38.5 for WWW issue and 6.41.3 for SMB). In order to upgrade many devices at the same time – you can use MikroTik tool called The Dude or use scripts.

From the above post, at least read the FAQ:

FAQ:

What is affected?

– Webfig with standard port 80 and no firewall rules
– Winbox has nothing to do with the vulnerability, Winbox port is only used by the scanners to identify MikroTik brand devices. Then it proceeds to exploit WEBFIG through port 80.

Am I safe? 

– If you upgraded your router in the last ~12 months, you are safe
– If you had “ip service” “www” disabled: you are safe
– If you had firewall configured for port “80”: you are safe
– If you only had Hotspot in your LAN, but Webfig was not available: you are safe.
– If you only had User Manager in your LAN, but Webfig was not available: you are safe.
– If you had other Winbox port before this: you are safe from the scan, but not from the infection.
– If you had “winbox” disabled, you are safe from the scan, not from the infection.

– If you had “ip service” “allowed-from” set to specific network: you are safe if that network was not infected.
– If you had “Webfig” visible to LAN network, you could be infected by an infected device in your LAN.

How to detect and cure?

– Upgrading to v6.38.5 or newer will remove the bad files, stop the infection and prevent anything similar in the future.
– If you upgrade device and you still see attempts to access Telnet from your network – run Tool/Torch and find out a source of the traffic. It will not be router itself, but another device in local network which also is affected and requires an upgrade.

–jeroen

Posted in Internet, MikroTik, Power User, routers, Security | Leave a Comment »

If I ever have to do bind named work again…

Posted by jpluimers on 2018/03/12

Boy, named can be cryptic.

So here are some links that might help me in the future

jeroen

Posted in *nix, bind-named, DNS, Internet, Linux, Power User | Leave a Comment »

WayBack throwing “Wayback Exception An unknown exception has occurred. Unexpected Error” usually indicates a cookie problem

Posted by jpluimers on 2017/12/22

If saving a web-page on the WayBack machine throws you this error on any site:

Wayback Exception

 

An unknown exception has occurred. Unexpected Error

Then usually the cause is having too many cookies.

Clean your cookies for web.archive.org, then try again.

–jeroen

Posted in Internet, InternetArchive, Power User, WayBack machine | 2 Comments »

The day that the internet archive was down for a few hours – time to sponsor them.

Posted by jpluimers on 2017/12/17

In an era where we’ve become dependent on 24/7 communications and availability of the internet, but even more so on archives of information that appeared, became fake and then denied, the Internet Archive (including the WayBack machine) was down for a few hours because of a PGE power outage in San Francisco.

(Posted late because, well the WordPress.com “missed schedule” bug is back)

So this is a reminder to sponsor the Internet Acrhive. Because we can.

–jeroen

Read the rest of this entry »

Posted in Internet, InternetArchive, Missed Schedule, Power User, SocialMedia, WayBack machine, WordPress | Leave a Comment »

DNS, glue records and TTL

Posted by jpluimers on 2017/12/06

If I ever need to read why, here are the explanatory links:

TL;DR:

  • You need glue records for your domains if the nameserver is in the same TLD as your domain is (more explanation in the above links).
  • Your domain registrar allows you to change both your DNS servers and the glue at the TLD servers.
  • Glue records have a TTL at the TLD of 48 hours so changing them takes some waiting.
  • This is how you query the glue records so you can verify what’s setup at your DNS servers matches the ones at the TLD servers (in the below examples, replace google.com by your domain name).

dig +trace +additional google.com

 

Notes:

At the time of writing the dig output is this:

Read the rest of this entry »

Posted in DNS, Internet, Power User | Leave a Comment »

DNS Knowledge DNS Tutorial, News and Tools: How to setup Quad9 DNS on a Linux

Posted by jpluimers on 2017/11/24

Reminder to self so I try this out: [Archive.isDNS Knowledge DNS Tutorial, News and Tools: How to setup Quad9 DNS on a Linux

Quad9 is a free security solution that uses DNS to protect your systems against the most common cyber threats and you can setup it on Linux.

Related: [Archive.is] Quad9 | Internet Security & Privacy In a Few Easy Steps:

Quad9 is a free security solution that uses DNS to protect your system against the most common cyber threats. It improves your system’s performance, plus, it preserves and protects your privacy. It’s like an immunization for your computer.

Via: [WayBack] Remember 8.8.8.8 (Google DNS)? Now we have 9.9.9.9 from IBM/Quad9 that brings together cyber threat intelligence about malicious domains…. – nixCraft – Google+

Remember 8.8.8.8 (Google DNS)? Now we have 9.9.9.9 from IBM/Quad9 that brings together cyber threat intelligence about malicious domains. It can block malware and other bad domains. https://www.dnsknowledge.com/tutorials/how-to-setup-quad9-dns-on-a-linux/ and https://quad9.net/#/ What do you think? Do you use Google DNS or OpenDNS or ISP DNS or newer Quad9 DNS?

–jeroen

Posted in *nix, DNS, Internet, Power User, Security | Leave a Comment »

OpenBSD on PC Engines APU2 | Hacker News

Posted by jpluimers on 2017/11/21

Via [WayBackOpenBSD on PC Engines APU2 | Hacker News and [WayBackIlya S – Google+ commenting at [WayBack] I am thinking about moving to BSD as my main OS – Joe C. Hecht – Google+:

Just in case I want to build my own router on PC Engines APU2 hardware: installation instructions at [Wayback/Archive] elad/openbsd-apu2: OpenBSD on the APU2

–jeroen

Posted in APU, Development, Hardware, Hardware Development, Internet, Network-and-equipment, Power User, routers | Leave a Comment »

DNS BIND9 acl clause – they *can* be nested

Posted by jpluimers on 2017/11/16

One of the use cases of DNS acl I needed involved having some data to be duplicated across acl.

So I was looking at some way to de-duplicate and found out the term for that is nesting which the bind acl allow.

–jeroen

Posted in DNS, Internet, Power User | Leave a Comment »

Some links on isolating parts of networks with Mikrotik

Posted by jpluimers on 2017/11/10

On my research list so I can do proper LoT.

–jeroen

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Posted in Development, Internet, MikroTik, Power User, RouterOS, routers, Scripting, Software Development | Leave a Comment »

How to connect S+DA0003 using SFP between MikroTikCRS226 and MikroTikCCR1009

Posted by jpluimers on 2017/10/30

Mikrotik and SFP versus SFTP+ is always confusing especially as the text on their equipment and their documentation doesn’t show well which situations work.

Equipment text is further on, this is their text searchable documentation:

As usually, a long search in the forums reveals the background information:

[WayBackSFP in SFP+ slot – MikroTik RouterOS: 10Gb SFP+ sockets are usually backward compatible with SFP, but this is not guaranteed.

There are two tricks involved to get an SFP connection between these devices working:

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Posted in Internet, MikroTik, Power User, routers | Leave a Comment »