Description:

When certain text appears in code block, server replaces it with random string

Steps to reproduce:

1. Open any chat
2. Paste following code block

cut '|' \
| sed 's|^\(.*\)$||' \
| sed 's|^\(.*\)$|<?xml version="1.0"?>|' \
| xxx "" \
| xxx "" \
>

Expected behavior:

The code block should be pasted unchanged

Actual behavior:

Part of second and third line is replaced with some random string

cut '|' \
| sed 's|^=!=4524mzNT3zPWa6Etr=!=$||' \
| sed 's|^=!=RNXGKGiXf43yTxppq=!=$|<?xml version="1.0"?>|' \
| xxx "" \
| xxx "" \
>

Server Setup Information:

• Version of Rocket.Chat Server: 1.2.3
• Operating System: Linux 4.19.0-5-amd64
• Deployment Method: tar
• Number of Running Instances: 3
• DB Replicaset Oplog:
• NodeJS Version: v8.11.4
• MongoDB Version: 3.6.13

Additional context

When the text is just slightly changed, the syntax formatting manner changes and following that, the bug disappears. Just replacing the cut word on begging with xxx affects this.

Also the instance on https://open.rocket.chat is affected

This bug is similar to already closed issue #1860

Relevant logs:

N/A