-----------------ORIGIN PACKET---------------
GET /expr/injection?a=1 HTTP/1.1
Host: vulinbox.bachang.org
Remote-Host: 3.142.242.51
X-Forwarded-Proto: https
Accept: */*
User-Agent: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
Accept-Encoding: gzip, br, zstd, deflate
X-Real-Ip: 3.142.242.51
X-Forwarded-For: 3.142.242.51

-----------------Handled---------------
a[1]: 1

b[]: 

b params is should be JSON!!!!!!!!!!!!!!!!!

c[]: last Stack Value is nil/undefined