How to correctly decrypt FTP (over TLS) traffic

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Announcements
Please sign in to see details of an important advisory in our Customer Advisories area.

How to correctly decrypt FTP (over TLS) traffic

L2 Linker

Hi,

I am facing the common issue of Passive FTP (over TLS). Basically, the connection fails due to the dynamic ports assigned in the encrypted channel. It is clear that the solution is to configure PA to decrypt the traffic to identify the dynamic port and PA automatically (and temporarily) will open the traffic for that port.

But unfortunately, I could not find detailed instructions for the implementation.

https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClEjCAK

 

I created a decryption rule for my only user with ANY in the service (see attachment) and the problem gets solved, but I didn't feel comfortable with the ANY so I tried filtering by FTP ports. I created a service called FTP Test with TCP 20 and 21 ports.

Doing this, the traffic did not match, didn't get decrypted and the FTPs connection failed to list the directory.

 

could you please help me out with the correct configuration?

 

Many thanks.

 



Please note you are posting a public message where community members and experts can provide assistance. Sharing private information such as serial numbers or company information is not recommended.
1 REPLY 1

Cyber Elite
Cyber Elite

Hello,

You would need to select the port/service that the traffic is being seen as prior to decryption. Best practice would be to decrypt all traffic and have exceptions to bypass encryption.

 

Hope this helps.

  • 2078 Views
  • 1 replies
  • 0 Likes
Like what you see?

Show your appreciation!

Click Like if a post is helpful to you or if you just want to show your support.

Click Accept as Solution to acknowledge that the answer to your question has been provided.

The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!

These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!

The LIVEcommunity thanks you for your participation!