topic Re: Disable weak cipher suite in SSH in General Topics

Disable weak cipher suite in SSH

dtran — Thu, 28 Oct 2021 17:14:36 GMT

I would like to disable weak cipher suite in SSH for over 100+ Firewalls with the following commands. The firewalls are running in High-Availability (H/A) mode, version 9.1.10:

configure
set deviceconfig system ssh ciphers mgmt aes256-ctr
set deviceconfig system ssh ciphers mgmt aes256-gcm
set deviceconfig system ssh default-hostkey mgmt key-type ECDSA 256
set deviceconfig system ssh regenerate-hostkeys mgmt key-type ECDSA key-length 256
set deviceconfig system ssh mac mgmt hmac-sha2-256
set deviceconfig system ssh mac mgmt hmac-sha2-512
set deviceconfig system ssh kex mgmt ecdh-sha2-nistp521

commit

exit

set ssh service-restart mgmt
exit

I would like to do this via script. However, when I look at PAN knowledgeable base, I see this:

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000PN5bCAG&lang=en_US

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA14u000000HAsiCAG

The solution provided is not scalable in my environment. Is there a better way? How do Managed Service Providers (MSP) handle this with lot of PAN firewalls.

Thoughts?

Re: Disable weak cipher suite in SSH

OtakarKlier — Thu, 28 Oct 2021 20:23:08 GMT

Hello,

I'm sure there are several ways to perform this task. Perhaps say a loop and feed it the list of firewalls?

Regards,

Re: Disable weak cipher suite in SSH

TomYoung — Thu, 28 Oct 2021 22:47:42 GMT

Hi @dtran ,

It is disappointing that these changes cannot be pushed from Panorama. However, you can push an SSH Service Profile and apply it to the management interface that effectively blocks those protocols.

With regard to the CLI, here is a similar (solved) thread -> https://live.paloaltonetworks.com/t5/general-topics/disable-weak-cipher-suites-for-ssl-tls-and-ssh/td-p/388126.

Thanks,

Tom

Re: Disable weak cipher suite in SSH

dtran — Fri, 29 Oct 2021 10:59:05 GMT

@TomYoung: The thread you mentioned can not be done via scripting. If you read closely, it stated "require console". Unfortunately, console is NOT available in AWS.

Re: Disable weak cipher suite in SSH

TomYoung — Fri, 29 Oct 2021 11:11:21 GMT

Hi @dtran ,

Correct. I added it for your reference, not as a solution. Theoretically, the commands can be done via SSH, but I would not close the current SSH session without testing with a new SSH session.

Thanks,

Tom

Re: Disable weak cipher suite in SSH

dtran — Fri, 29 Oct 2021 13:18:53 GMT

@TomYoung: Thank you. Can you also elaborate on the SSH service profile? How do I go about doing this?

Re: Disable weak cipher suite in SSH

TomYoung — Fri, 29 Oct 2021 13:27:35 GMT

Hi @dtran ,

Sure! This feature was introduced in 10.0. Create the profile under Device > Certificate Management > SSH Service Profile, and apply it under Device > Setup > Management > SSH Management Profile Setting. You configure what algorithms are allowed.

https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-admin/certificate-management/configure-an-ssh-service-profile

Thanks,

Tom

Re: Disable weak cipher suite in SSH

dtran — Fri, 29 Oct 2021 13:33:02 GMT

@TomYoung: Unfortunately, that will not help me. I am currently running 9.1.10, and we're not going to 10.x anytime soon ☹️.