DDOs postgresql or what's going on?

Question

PostgreSQL

I have postgres in my docker, the default user is disabled, the port remains the default, it crashes from time to time. According to the logs, I first see the tones of such messages

2020-02-14 17:26:38.505 UTC [62] FATAL:  password authentication failed for user "postgres"
2020-02-14 17:26:38.505 UTC [62] DETAIL:  Password does not match for user "postgres".
        Connection matched pg_hba.conf line 95: "host all all all md5"

And then this happens, and everything in the db remains untouched, I have an assumption that the script walks around the network and tries to log in to my database, but maybe something else? I'm going to change the port, but how else can I protect myself from this and what is it all about?

2020-10-16 12:03:33.965 UTC [599] FATAL:  no PostgreSQL user name specified in startup packet
2020-10-16 23:02:43.635 UTC [1916] FATAL:  password authentication failed for user "postgres"
2020-10-16 23:02:43.635 UTC [1916] DETAIL:  Role "postgres" does not exist.
  Connection matched pg_hba.conf line 99: "host all all all md5"
2020-10-16 23:10:51.361 UTC [1933] LOG:  invalid length of startup packet
2020-10-17 06:53:09.429 UTC [2857] FATAL:  unsupported frontend protocol 65363.19778: server supports 2.0 to 3.0
2020-10-17 07:50:38.203 UTC [2973] FATAL:  unsupported frontend protocol 0.0: server supports 2.0 to 3.0
2020-10-17 07:50:38.241 UTC [2974] FATAL:  unsupported frontend protocol 255.255: server supports 2.0 to 3.0
2020-10-17 07:50:38.281 UTC [2975] FATAL:  no PostgreSQL user name specified in startup packet
2020-10-17 09:02:51.192 UTC [3120] FATAL:  password authentication failed for user "root"
2020-10-17 09:02:51.192 UTC [3120] DETAIL:  Role "root" does not exist.
  Connection matched pg_hba.conf line 99: "host all all all md5"
2020-10-17 22:23:05.786 UTC [4723] FATAL:  unsupported frontend protocol 0.0: server supports 2.0 to 3.0
2020-10-17 22:23:05.825 UTC [4724] FATAL:  unsupported frontend protocol 255.255: server supports 2.0 to 3.0
2020-10-17 22:23:05.869 UTC [4725] FATAL:  no PostgreSQL user name specified in startup packet
2020-10-18 06:06:44.284 UTC [1] LOG:  received fast shutdown request
2020-10-18 06:06:44.297 UTC [1] LOG:  aborting any active transactions
2020-10-18 06:06:44.339 UTC [1] LOG:  background worker "logical replication launcher" (PID 30) exited with exit code 1
11:08
[2020-10-17 15:12:29 +0000] [1] [CRITICAL] WORKER TIMEOUT (pid:10)
[2020-10-17 15:12:29 +0000] [10] [INFO] Worker exiting (pid: 10)
[2020-10-17 15:12:29 +0000] [18] [INFO] Booting worker with pid: 18
[2020-10-18 06:06:44 +0000] [1] [INFO] Handling signal: term
[2020-10-18 06:06:44 +0000] [8] [INFO] Worker exiting (pid: 8)
[2020-10-18 06:06:44 +0000] [9] [INFO] Worker exiting (pid: 9)
[2020-10-18 06:06:44 +0000] [11] [INFO] Worker exiting (pid: 11)
[2020-10-18 06:06:44 +0000] [18] [INFO] Worker exiting (pid: 18)
[2020-10-18 06:06:45 +0000] [1] [INFO] Shutting down: Master

Answer 1

The basis basically should not be available on the external interface. DoS on authorization is arranged by elementary spam of connection requests, you don’t even need distributed.