__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Cisco ACS Acme.server traversal Vulnerability [Cisco Security Advisory: CSCdu47965] July 3, 2002 17:00 GMT Number M-097 [Revised 9 July 2002] ______________________________________________________________________________ PROBLEM: A vulnerability exists within the Acme.server program that is part of the Cisco Secure Access Control Server Unix installation. These systems are vulnerable to a directory traversal vulnerability. PLATFORM: Cisco Secure ACS for Unix Servers version 2.0 through 2.3.5.1 DAMAGE: This vulnerability could allow an attacker to view files and directory structures on the target system. SOLUTION: Apply available patch or update to a patched version. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. Cisco encourages users to upgrade to a ASSESSMENT: fixed version of the software. Customers who may have been vulnerable to attack are advised to review privileged accounts and any suspicious database changes, and to change administrative passwords. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/m-097.shtml ORIGINAL BULLETIN: http://www.cisco.com/warp/public/707/acmeweb-acsunix-dirtravers-vuln-pub.shtml PATCHES: - 9 July, 2002 ftp://ftpeng.cisco.com/ftp/csu/Acme-Patch.tar.Z ______________________________________________________________________________ [***** Start Cisco Security Advisory: CSCdu47965 *****] Security Advisory: Cisco Secure ACS Unix Acme.server Information Disclosure Vulnerability ========================================================================= Revision 1.1 For Public Release 2002 July 2 10:00 (UTC -0800 ) Last Updated 2002 July 3 01:00 GMT ------------------------------------------------------------------------ Summary ======= Cisco Secure Access Control Server for Unix implements the Acme.server and is therefore vulnerable to a directory traversal vulnerability. The fix has been included in ACS Unix version 2.3.6.1 which is currently available. This vulnerability is detailed in Cisco Bug ID CSCdu47965. This advisory is available at: http://www.cisco.com/warp/public/707/acmeweb-acsunix-dirtravers-vuln-pub.shtml. Affected Products ================= The defects described in this document are present in releases beginning with version 2.0 up to and including version 2.3.5.1 of Cisco Secure ACS for Unix Server. Cisco Secure ACS for Windows NT is not vulnerable to this issue. Cisco Access Registrar is not vulnerable to this issue. Details ======= This vulnerability exists within the Acme.server program that is part of the Cisco Secure ACS Unix installation. This vulnerability has been repaired in the Acme.server utility. The patch is available for Cisco customers, and has now been incorporated into the Cisco Secure ACS Unix product. The vulnerability is triggered when someone browses to the server URL and adds trailing slashes as in the following example: http://servername:9090///. This exploit will display the files and filesystem of the target server. This vulnerability has been assigned Cisco bug ID CSCdu47965. Impact ====== The impact may vary, depending whether potential attackers have access to port 9090 on the Cisco Secure ACS computer. This vulnerability could allow an attacker to view files and directory structures on the target system. Access to the encrypted password file provided by this vulnerability, for example, would allow an attacker access through a successful dictionary attack against the listed accounts. Customers who may have been vulnerable to attack are advised to review privileged accounts and any suspicious database changes, and to change administrative passwords. Software Versions and Fixes =========================== There is a patch available, and the fixes are included in Cisco Secure ACS Unix version 2.3.6.1 and all versions going forward. For existing versions, the patch may be applied, which resolves the issue. There is no need to upgrade to a newer version. Obtaining Fixed Software ======================== Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on the Cisco worldwide website at http://www.cisco.com/cgi-bin/tablebuild.pl/cs-acs. Customers whose Cisco products are provided or maintained through prior or existing agreement with third-party support organizations such as Cisco Partners, authorized resellers, or service providers should contact that support organization for assistance with the upgrade, which should be free of charge. Customers who purchase direct from Cisco but who do not hold a Cisco service contract and customers who purchase through third-party vendors but are unsuccessful at obtaining fixed software through their point of sale should get their patch upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows: +1 800 553 2447 (toll-free from within North America) +1 408 526 7209 (toll call from anywhere in the world) or by email: tac@cisco.com . Please have your product serial number available and give the URL of this notice as evidence of your entitlement to the patched software. Patch requests for non-contract customers must be requested through the TAC. Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades or software patches. Workarounds =========== Workarounds for this vulnerability include general recommendations of protecting the Cisco Secure ACS for Unix with strong firewalls, access controls, and preventing any external or unauthenticated access to the system, and to port 9090 in particular. This is an interim workaround only, and a patch or upgrade is recommended. For this issue, a patch is available which may be installed in place of an upgrade. The patch is available at the following temporary location: ftp://ftpeng.cisco.com/ftp/csu/Acme-Patch.tar.Z For any assistance with the patch, please contact the TAC. This patch fixes the security problem with the Acme.server. It includes the modified files provided by Acme. This patch can be applied for any supported version of Cisco Secure, that is, CiscoSecure/Unix 2.3(3) or later. The patch consists of one file: FastAdmin/Acme.zip. Patch Installation Instructions To install the patch, follow the instructions below. The commands need to be executed on your Cisco Secure ACS Unix by the administrator. 1. Stop Cisco Secure by entering the command: /etc/rc0.d/K80CiscoSecure 2. Change to the base directory where Cisco Secure is installed. cd $BASEDIR 3. Copy the compressed tar file Acme-Patch.tar.Z into the current directory. 4. Uncompress and untar the file. uncompress Acme-Patch.tar.Z tar xvf Acme-Patch.tar 5. Start Cisco Secure with the command: /etc/rc2.d/S80CiscoSecure Exploitation and Public Announcements ===================================== The issue with the Acme.server was posted to the Bugtraq list June 2001 http://online.securityfocus.com/archive/1/188141, although no specific mention of the Cisco product was made in the original posting. Cisco PSIRT is not aware of any malicious use of the vulnerability described in this advisory. Status of This Notice: FINAL ============================ This is a final field notice. Although Cisco cannot guarantee the accuracy of all statements in this notice, all the facts have been checked to the best of our ability. Cisco does not anticipate issuing updated versions of this notice unless there is some material change in the facts. Should there be a significant change in the facts, Cisco may update this notice. Distribution ============ This notice will be posted on the Cisco worldwide website at http://www.cisco.com/warp/public/707/acmeweb-acsunix-dirtravers-vuln-pub.shtml. In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients: * cust-security-announce@cisco.com * bugtraq@securityfocus.com * first-teams@first.org (includes CERT/CC) * cisco@spot.colorado.edu * comp.dcom.sys.cisco * firewalls@lists.gnac.com * Various internal Cisco mailing lists Future updates of this notice, if any, will be placed on Cisco's worldwide web server, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the URL given above for any updates. Revision History ================ Revision 1.1 2002 July 3 - 01:00 Update to Workarounds section Revision 1.0 2002 July 2 - 10:00 Initial Public Release Cisco Security Procedures ========================= Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at http://www.cisco.com/warp/public/707/sec_incident_response.shtml. This includes instructions for press inquiries regarding Cisco security notices. All Cisco Security Advisories are available at http://www.cisco.com/go/psirt. ------------------------------------------------------------------------ This notice is Copyright 2002 by Cisco Systems, Inc. This notice may be redistributed freely after the release date given at the top of the text, provided that redistributed copies are complete and unmodified, and include all date and version information. ------------------------------------------------------------------------ [***** End Cisco Security Advisory: CSCdu47965 *****] _______________________________________________________________________________ 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. 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