__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Cisco IOS Line Printer Daemon (LPD) Vulnerability [Cisco Security Advisory Document ID: 99109] October 15, 2007 18:00 GMT Number S-013 ______________________________________________________________________________ PROBLEM: There is a stack overflow in the Cisco IOS Line Printer Daemon (LPD) Protocol feature. PLATFORM: All versions of IOS that support the LPD functionality except the ones listed below are affected. DAMAGE: May allow an attacker to execute arbitrary code or create a denial-of-service condition. SOLUTION: Upgrade to the appropriate version. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. May allow an attacker to execute arbitrary ASSESSMENT: code or create a denial-of-service condition. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/s-013.shtml ORIGINAL BULLETIN: http://www.cisco.com/warp/public/707/cisco-sr-20071010-lpd.shtml ______________________________________________________________________________ [***** Start Cisco Security Advisory Document ID: 99109 *****] Cisco Security Response: Cisco IOS Line Printer Daemon (LPD) Protocol Stack Overflow Document ID: 99109 http://www.cisco.com/warp/public/707/cisco-sr-20071010-lpd.shtml Revision 1.0 For Public Release 2007 October 10 1600 UTC (GMT) -------------------------------------------------------------------------------- Please provide your feedback on this document. -------------------------------------------------------------------------------- Contents Cisco Response Additional Information Revision History Cisco Security Procedures -------------------------------------------------------------------------------- Cisco Response This is the Cisco Product Security Incident Response Team (PSIRT) response to an issue discovered and reported to Cisco by Andy Davis from IRM, Plc. regarding a stack overflow in the Cisco IOS Line Printer Daemon (LPD) Protocol feature. The original post is available at the following link: http://www.irmplc.com/index.php/155-Advisory-024 Cisco greatly appreciates the opportunity to work with researchers on security vulnerabilities, and welcome the opportunity to review and assist in product reports. Additional Information Cisco has confirmed the security research's findings and has documented this issue in Cisco Bug ID CSCsj86725 ( registered customers only) . All versions of IOS that support the LPD functionality except the ones listed below are affected. Customers that do not enable the LPD functionality are not affected. Note: LPD is disabled by default on Cisco IOS routers. If LPD services are configured, then one or more global printer command lines would be present in the router's configuration. No other Cisco products are currently known to be affected by this vulnerability. This issue has been fixed on versions 12.2(18)SXF11, 12.4(16a), 12.4(2)T6 and later. For more information please view the bug's details via the Bug Toolkit on Cisco.com. Workaround If LPD services are not required, they can be disabled by using the no printer command; thus, eliminating this vulnerability. Note: LPD is disabled by default on Cisco IOS routers. In addition, LPD uses TCP port 515. An access control list (ACL) can be configured to only allow trusted devices to communicate to the router via TCP port 515. THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. Revision History Revision 1.0 2007-October-10 Initial public release. [***** End Cisco Security Advisory Document ID: 99109 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Cisco for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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