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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2000.238 -- FreeBSD-SA-00:44 xlockmore port allows reading of password file 30 August 2000 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: xlockmore Vendor: FreeBSD Ports Collection Operating System: FreeBSD Linux Unix Platform: N/A Impact: Reduced Security Access Required: Local - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-00:44 Security Advisory FreeBSD, Inc. Topic: xlockmore port allows reading of password file Category: ports Module: xlockmore Announced: 2000-08-28 Credits: bind <bind@SUBTERRAIN.NET> Affects: Ports collection prior to the correction date. Corrected: 2000-08-15 Vendor status: Updated version released FreeBSD only: NO I. Background xlockmore is a utility for locking console access to an X terminal. II. Problem Description The xlockmore port, versions 4.17 and below, installs the setuid root binary xlock, which contains a vulnerability due to incorrect use of the syslog() function. The xlock program correctly drops root privileges prior to the point of vulnerability, however it may retain in memory part of the hashed password database for the user accounts on the system. Attackers who can retrieve hashed password information from the memory space of the process can mount attacks against the user account passwords and possibly gain access to accounts on the system if successful. The xlockmore port is not installed by default, nor is it "part of FreeBSD" as such: it is part of the FreeBSD ports collection, which contains over 3700 third-party applications in a ready-to-install format. The ports collections shipped with FreeBSD 3.5-RELEASE and 4.1-RELEASE 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 Unprivileged local users may be able to gain unauthorised access to parts of the /etc/spwd.db file, allowing them to mount guessing attacks against user passwords. If you have not chosen to install the xlockmore port/package, then your system is not vulnerable to this problem. IV. Workaround One of the following: Deinstall the xlockmore port/package, if you have installed it. V. Solution One of the following: 1) Upgrade your entire ports collection and rebuild the xlockmore 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/x11/xlockmore-4.17.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/x11/xlockmore-4.17.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/x11/xlockmore-4.17.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/x11/xlockmore-4.17.1.tgz ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/x11/xlockmore-4.17.1.tgz NOTE: It may be several days before updated packages are available. 3) download a new port skeleton for the xlockmore 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 - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBOaqzxFUuHi5z0oilAQEJJgP/cpBPXxsnmcGysBYnZkq0+mhMYxxDyX/D czvyS90uO3k9slC+QYsmgLeTRrDpULcHNsePwxYKbt+zEydcENLhpiiGRuGkKrvD b5UH9Sjle3rF3nTecxKRPTPD0009Tk356YeYOPVofqfZzCQpR8MqUHGz9cmhBuXH t/y3LtBhLDo= =sJTv - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the original authors to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBOcd2+Ch9+71yA2DNAQEChwP/fxRRIDfNw+I9iBQoe8zpQvLK1d7Qr7xL r3hQLkFHe7eK8T8sTdO8HtF2XMuprkLq5EcSzjceu6CF2aVcsQqOOySra34+W7ci Y3rOgrEWSbN15AqE/WGBhuCSvPJAL+5jO7jG8aUfjLmGoMovqtCty/T60UpNGMaJ ZkpqBczltwI= =9FtT -----END PGP SIGNATURE-----