CUCM Backup fails to a specific SFTP server

[nedudaniels]

Hello,

I manage two clusters, Cluster A and Cluster B connected over a WAN.
Cluster A has a publisher and 8 Subscribers
Cluster B has a publisher and a Subscriber

• CUCM in cluster B is UNABLE to backup to SFTP server in Cluster B network. Error message is "update failed :       unable to access sftp server. Please ensure the username and password are correct"
• CUCM in cluster B is able to backup to SFTP Server in cluster A network
• CUCM in Cluster A is able to backup to STFP server in cluster B network

I use Solarwinds as SFTP server solution. I also tried Coreftp, but got the same result.
I have checked to ensure there are no restrictions on the network either by firewall or otherwise.

What could be causing this? Are there troubleshooting methods I can try?

[Roger Kallberg]

If it was working why did you update it? For us it’s working a charm, but we have not touched it ever since we installed it.

[shkabdlh]

As per the security advisory for vulnerabilities.

[Roger Kallberg]

By what I can find the latest vulnerability discovered in this application is from way back in 2018.

 
Do you have any reference for any newly discovered vulnerabilities?

[sudaggar]

could you please share DRF master and DRF local logs (logs level set to detailed in serviceability page) from RTMT for non working cluster.

Regards

[stevenlandon]

what version of CUCM?

I use OpenSSH on an Ubuntu server and it is rock solid...does require a little linux comfortability.

one thing to keep in mind is that some modern SSH/SFTP servers will not support older authentication standards.

If you are running an older version of CUCM, make sure you have the latest patch. Even then, you may still have the issue. You may need to enable older encryption standards in your SFTP server.