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:-
?env">Environment

?inc">Loaded Modules

?inh_tree">Inheritance Tree

?isa_tree">ISA Tree

?myconfig">Perl Configuration

?rgysubs">Compiled Registry Scripts

?script">PerlRequire'd Files

?sig">Signal Handlers

?symdump">Symbol Table Dump




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:

Copyright 2009 Procheckup Ltd. All rights reserved.

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Any other use of this information is prohibited. Procheckup is not liable for any misuse  of this information by any third party.