Snort reports "Sid 128-1" when pushing to gitlab

Summary

The other day, I tried to push something to gitlab.com from behind my company's firewall (snort.org (that's the firewall, not my company)). This was working fine a few weeks ago, and gitlab.com is not blocked in my company's network. However, when I tried to push, this happened:

git push --set-upstream origin development

Counting objects: 28, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (23/23), done.
Writing objects:  21% (6/28)   
packet_write_wait: Connection to 35.231.145.151 port 22: Broken pipe
fatal: The remote end hung up unexpectedly
fatal: The remote end hung up unexpectedly

After that, gitlab.com was not reachable anymore from our network, so I asked our sysadmin what was going on. He said that our firewall detected a potential attack and blocked the host. This was the detected potential attack: https://www.snort.org/rule_docs/128-1

Steps to reproduce

1. Be in a network that is protected with snort
2. Push something to gitlab

What is the current bug behavior?

Firewall detects an attempt to exploit a known vulnerability in OpenSSH.

What is the expected correct behavior?

Firewall should not detect anything

Relevant logs and/or screenshots

See console output and detected issue in the summary

Output of checks

This bug happens with GitLab.com