Fix issue in Redis modules when run against authenticated instances

[smashery]

Redis modules that use the redis_command method fail when authentication is present on the Redis instance. By adding in extra error logging, we can see the cause:

msf6 auxiliary(scanner/redis/file_upload) > run                                                                   
                                                                                                                  
[-] 127.0.0.1:6379        - Auxiliary failed: NameError undefined local variable or method `auth_response' for #<Msf::Modules::Auxiliary__Scanner__Redis__File_upload::MetasploitModule:0x000055b2fe31c638>
Did you mean?  author_to_s                       [-] 127.0.0.1:6379        - Call stack:                                                                           
[-] 127.0.0.1:6379        -   /home/smash/git/metasploit-framework/lib/msf/core/auxiliary/redis.rb:57:in `redis_command'
[-] 127.0.0.1:6379        -   /home/smash/git/metasploit-framework/modules/auxiliary/scanner/redis/file_upload.rb:122:in `check'
[-] 127.0.0.1:6379        -   /home/smash/git/metasploit-framework/modules/auxiliary/scanner/redis/file_upload.rb:158:in `run_host'
[-] 127.0.0.1:6379        -   /home/smash/git/metasploit-framework/lib/msf/core/auxiliary/scanner.rb:121:in `block (2 levels) in run'
[-] 127.0.0.1:6379        -   /home/smash/git/metasploit-framework/lib/msf/core/thread_manager.rb:105:in `block in spawn'
[*] Auxiliary module execution completed

This was a result of moving the regex into a constant, which broke named captures:

20f4050#diff-93e4bb8f08966b468043dde216d65c0afa081c6e530193b2e6578b96e8aa8103

[smashery]

To reproduce the issue, create a redis service with a password. An easy way to do that is using the Redis docker container:

docker run -d -p 6379:6379 --name redis redis --requirepass abcde

Then in MSF:

> use auxiliary/gather/redis_extractor
> set rhosts localhost
> set password abcde
> run

[adfoster-r7]

Tested with scanner/redis/file_upload and auxiliary/gather/redis_extractor, and it's working great - thanks! 👍

[adfoster-r7]

Release Notes

Updated the auxiliary/scanner/redis/file_upload module to correctly handle Redis instances which require authenticated access.