__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN FreeBSD LPRng Vulnerability October 13, 2000 19:00 GMT Number L-004 ______________________________________________________________________________ PROBLEM: A vulnerability exists in the 'syslog(3) function of LPRng, versions prior to 3.6.24. PLATFORM: FreeBSD 3.5.1, 4.1, & 4.1.1. DAMAGE: Using string-formatting operators a malicious user may gain root access. SOLUTION: Either remove the software from the system, or apply the patch offered by FreeBSD. ______________________________________________________________________________ VULNERABILITY The risk is LOW. This vulnerability is publicly known, ASSESSMENT: however no incidents have been reported. ______________________________________________________________________________ [****** Begin FreeBSD Advisory ******] FreeBSD-SA-00:56 Security Advisory FreeBSD, Inc. Topic: LPRng contains potential root compromise Category: ports Module: LPRng Announced: 2000-10-13 Credits: Chris Evans Affects: Ports collection prior to the correction date. Corrected: 2000-10-13 Vendor status: Updated version released FreeBSD only: NO I. Background LPRng is a popular printer daemon. II. Problem Description The LPRng port, versions prior to 3.6.24, contains a potential vulnerability which may allow root compromise from both local and remote systems. The vulnerability is due to incorrect usage of the syslog(3) function. Local and remote users can send string-formatting operators to the printer daemon to corrupt the daemon's execution, potentially gaining root access. The LPRng port is not installed by default, nor is it "part of FreeBSD" as such: it is part of the FreeBSD ports collection, which contains nearly 4000 third-party applications in a ready-to-install format. The ports collections shipped with FreeBSD 3.5.1, 4.1 and 4.1.1 contain this problem since it was discovered after the releases. FreeBSD makes no claim about the security of these third-party applications, although an effort is underway to provide a security audit of the most security-critical ports. III. Impact Local and remote users may potentially gain root privileges on systems using LPRng. If you have not chosen to install the LPRng port/package, then your system is not vulnerable to this problem. IV. Workaround Deinstall the LPRng port/package, if you you have installed it. V. Solution One of the following: 1) Upgrade your entire ports collection and rebuild the LPRng port. 2) Deinstall the old package and install a new package dated after the correction date, obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/sysutils/LPRng-3.6.25.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/sysutils/LPRng-3.6.25.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/sysutils/LPRng-3.6.25.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/sysutils/LPRng-3.6.25.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/sysutils/LPRng-3.6.25.tgz NOTE: It may be several days before updated packages are available. 3) download a new port skeleton for the cvsweb port from: http://www.freebsd.org/ports/ and use it to rebuild the port. 4) Use the portcheckout utility to automate option (3) above. The portcheckout port is available in /usr/ports/devel/portcheckout or the package can be obtained from: ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5- current/devel/portcheckout-2.0.tgz [****** End FreeBSD Advisory ******] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of FreeBSD, Inc. 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 FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@llnl.gov For emergencies and off-hour assistance, DOE, DOE contractor sites, and the NIH may contact CIAC 24-hours a day. During off hours (5PM - 8AM PST), use one of the following methods to contact CIAC: 1. Call the CIAC voice number 925-422-8193 and leave a message, or 2. Call 888-449-8369 to send a Sky Page to the CIAC duty person or 3. Send e-mail to 4498369@skytel.com, or 4. Call 800-201-9288 for the CIAC Project Leader. Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ (or http://ciac.llnl.gov -- they're the same machine) Anonymous FTP: ftp.ciac.org (or ciac.llnl.gov -- they're the same machine) Modem access: +1 (925) 423-4753 (28.8K baud) +1 (925) 423-3331 (28.8K baud) 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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