Title: Xerox DC260 EFI Fiery Controller Webtools 2.0 Arbitrary File Disclosure
Advisory ID: ZSL-2017-5447
Type: Local/Remote
Impact: Exposure of System Information, Exposure of Sensitive Information
Risk: (4/5)
Release Date: 27.12.2017

Summary

Drive production profitability with Fiery servers and workflow products. See which Fiery digital front end is right for your current or future print engines and business needs. Manage all your printers from a single screen using this intuitive print job management interface.

Description

Input passed thru the 'file' GET parameter in 'forceSave.php' script is not properly sanitized before being used to read files. This can be exploited by an unauthenticated attacker to read arbitrary files on the affected system.

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/wt3/js/save.js:
----------------

103: function parseSaveMessages() {
104: var urlNode = saveDocument.getElementsByTagName('url').item(0);
105: var url = urlNode.firstChild.data;
106: var forcedSaveUrl = "forceSave.php?file=" + url;
107: window.open(forcedSaveUrl, 'save_iframe', 'width=1,height=1');


/wt3/forceSave.php:
-------------------
1. <?php
2. //code posted by chrisputnam at gmail dot com
3. function readfile_chunked($filename,$retbytes=true)
4. {
5. $chunksize = 1*(1024*1024); // how many bytes per chunk
6. $buffer = '';
7. $cnt =0;
8. // $handle = fopen($filename, 'rb');
9. $handle = fopen($filename, 'rb');
10. if ($handle === false)
11. {
12. return false;
13. }
14. while (!feof($handle))
15. {
16. //read a chunk
17. $buffer = fread($handle, $chunksize);
18. //send the chunk
19. echo $buffer;
20. //flush the chunk
21. flush();
22. //increment the size read/sent
23. if ($retbytes)
24. {
25. $cnt += strlen($buffer);
26. }
27. }
28. //close file
29. $status = fclose($handle);
30. if ($retbytes && $status)
31. {
32. return $cnt; // return num. bytes delivered like readfile() does.
33. }
34. return $status;
35. }
36.
37. $filename = $_GET['file'];
38. if(!$filename)
39. {
40. echo "ERROR: No filename specified. Please try again.";
41. }
42. else
43. {
44. // fix for IE caching or PHP bug issue
45. header("Pragma: public");
46. header("Expires: 0"); // set expiration time
47. header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
48. // browser must download file from server instead of cache
49.
50. // force download dialog
51. header("Content-Type: application/force-download");
52. header("Content-Type: application/octet-stream");
53. header("Content-Type: application/download");
54.
55. // use the Content-Disposition header to supply a recommended filename and
56. // force the browser to display the save dialog.
57. header("Content-Disposition: attachment; filename=" . basename($filename) . ";");
58. header("Content-Transfer-Encoding: binary");
59.
60. header("Content-Length: " . filesize($filename));
61.
62. set_time_limit(0);
63. readfile_chunked($filename, false);
64.
65. exit();
66. }
67.
68. ?>

--------------------------------------------------------------------------------

Vendor

Electronics for Imaging, Inc. - http://www.efi.com

Affected Version

EFI Fiery Controller SW2.0
Xerox DocuColor 260, 250, 242

Tested On

Debian GNU/Linux 3.1
Apache
PHP/5.4.41

Vendor Status

N/A

PoC

efifiery_fd.txt

Credits

Vulnerability discovered by Gjoko Krstic - <gjoko@zeroscience.mk>

References

[1] https://packetstormsecurity.com/files/145570
[2] https://www.exploit-db.com/exploits/43398/
[3] https://cxsecurity.com/issue/WLB-2017120295
[4] https://exchange.xforce.ibmcloud.com/vulnerabilities/137018

Changelog

[27.12.2017] - Initial release
[04.01.2018] - Added reference [1], [2], [3] and [4]

Contact

Zero Science Lab

Web: http://www.zeroscience.mk
e-mail: lab@zeroscience.mk