SSH Client Cannot Connect UBNT devices

[doush]

SSH Client cannot connect AirOS v5.5.8 devices also few other SNR switches.

Seems like a cipher problem on the RouterOS side.

[admin@MikroTik] > /sys ssh 10.20.2.8
DH_compute_key failed err: error:05066066:lib(5):func(102):reason(102)

[Ticket#2014012866000869]

Mikrotik Team ?

[normis]

Looks like their DH key strength is too low. RouterOS doesn’t allow such low security level.

[edmuxas]

UBNT has upgraded dropbear from used v0.51 to v2013.59 version. Here is dropbear change log (https://matt.ucc.asn.au/dropbear/CHANGES). Do you think newer dropbear version started to use weaker keys to “increase” security level?

One of the lines say that blowfish is disabled by default. Is it what RouterOS is using?

Thanks!

[doush]

@edmuxas

UBNT has upgraded dropbear from used v0.51 to v2013.59 version. Here is dropbear change log (https://matt.ucc.asn.au/dropbear/CHANGES). Do you think newer dropbear version started to use weaker keys to “increase” security level?

One of the lines say that blowfish is disabled by default. Is it what RouterOS is using?

Thanks!

Mikrotik ?

[planetcaravan]

I’ve noticed the problem is on a particular Ubiquiti build.
Here is what I have on Ubiquiti

Firmware Version: XW.v5.5.6
Build Number: 18861

Dropbear server v2013.58

On previous build (17762) SSH problem was not present!