______________________________________________________________________________ SuSE Security Announcement Package: samba Announcement-ID: SuSE-SA:2003:025 Date: Monday, Apr 7th 2003 21:00 MEST Affected products: 7.1, 7.2, 7.3, 8.0, 8.1, 8.2 SuSE Linux Database Server, SuSE eMail Server III, 3.1 SuSE Linux Enterprise Server 7, 8 SuSE Linux Firewall on CD/Admin host SuSE Linux Connectivity Server SuSE Linux Office Server Vulnerability Type: remote root access Severity (1-10): 7 SuSE default package: no Cross References: CAN-2003-0201 Content of this advisory: 1) security vulnerability resolved: samba problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds: - glibc - vnc 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information Digital Defense Inc. have discovered a buffer overflow in the samba file server, the widely spread implementation of the SMB protocol. The flaw allows a remote attacker to execute arbitrary commands as root on a server that runs a vulnerable version of samba. The vulnerability is known as DDI trans2.c overflow bug and is assigned the CVE ID CAN-2003-0201. Since this vulnerability was found during an analysis of an exploit happening in the wild, it should be assumed that exploits are circulating in the internet. A possible workaround is to restrict access using the "hosts allow" directive in the smb.conf file to a group of trusted hosts/addresses that should be able to access the server. Please see the sbm.conf(5) manpage ("man smb.conf") for more details about such configuration changes. It should be noted that each change of the configuration requires restarting/reloading the samba daemon ("rcsmb reload"). The only efficient and permanent remedy for the vulnerability should be to install the provided update packages from locations as listed below. It should be noted that this announcement is not a re-release of SuSE Security Announcement SuSE-SA:2003:016. While the update packages that are subject of this announcement (SuSE-SA:2003:025) also cover the problems fixed with SuSE-SA:2003:016, it announces fixes for a different vulnerability in addition. Therefore, the update packages must be installed again. Please note that the package names for SuSE products vary for different products. There exist the following pairings: server client ---------------------------- samba smbclnt samba samba-client samba-classic samba-classic-client samba-ldap samba-ldap-client To find out which packages are installed on your system, you may run the following command: rpm -qa|egrep '(samba|smbclnt)' Please download the update package for your distribution and verify its integrity by the methods listed in section 3) of this announcement. Then, install the package using the command "rpm -Fhv file.rpm" to apply the update. Our maintenance customers are being notified individually. The packages are being offered to install from the maintenance web. SPECIAL INSTALL INSTRUCTIONS: ============================= After successfully installing the update packages, you should restart the samba server process(es) to make the changes in the system effective. If you do not have a samba server running on your system, no further action is required. If you have a samba server running, please run the following command as root: rcsmb try-restart This will restart the samba daemon(s) if such daemon(s) are already running. Intel i386 Platform: SuSE-8.2: 40d47bed1d286f77d61503d93b48e276 e6da6fc3da94548d8460f43193a493c9 patch rpm(s): 3105a12895ca956b4ab29c15dbfdc1d2 d0418a25a2ea67c9577e23597a4c272d source rpm(s): 3e8dc087f8574f3d1259e020d6c005a6 SuSE-8.1: 684d7a7fff1f397736e3298d5a8c583d 7d9d9da83c5b8e6f049a5eb9a36d05e2 patch rpm(s): 905b3c3c4803457738aed00892d854bb 130d01b588d36576e1fbbce573a9bc86 source rpm(s): 71b90b54594f9e392cd5dcd5d750496a SuSE-8.0: a9ab49893027c3acd665e59ccecb6231 4920d2f7edbf66b8196133469d32fd24 patch rpm(s): bbde3c06e09d37def8f035161b8c932d 70228df7686f1494fc44cbaa838720bf source rpm(s): eb8d2a7e6b8f43d19388f28afa1b9812 SuSE-7.3: 965b260e660224d61c16ffb78a47fdfa bf20ce9c220f9a939aa43e2445a2142e source rpm(s): bac7ada7dc2e3b5e238211fb181f4e32 SuSE-7.2: 210da4fa4e1d601e78236d93e6abf5ac be819b970c2238a6d3c89e9f7f6dcb5f source rpm(s): b04e7eec150c1ba519605b522e1da25b SuSE-7.1: de27cbd77c32d2d29e77a518ca09c60d b020a46952c87b61d66cbc38c340155e source rpm(s): 45e6245a2fe47c430104671f41dc1a80 Sparc Platform: SuSE-7.3: 2fa50186e7ff2ecb2f8ddebf2355efe4 057d67ddd8fc56a82fe592dcb4928e7e source rpm(s): 7bcdd1c7a782f311292ca5214422fdc5 AXP Alpha Platform: SuSE-7.1: 6f88500a14ac86a6692788331b7aa626 a4444318b224b42137f017c0840ecd0f source rpm(s): 5c15b09bc46cb550a320575bc833daf5 PPC Power PC Platform: SuSE-7.3: 5018c3418c8706a29e8f036eb006922f bd02b033055f87b5f4325e1a6bd4dca7 source rpm(s): 88c8a521103ae268843b951c0ca36669 SuSE-7.1: f78fe93753c2e230ab4c870bffe5a7f2 17def1f1b5a3514252187a9a0b250bf9 source rpm(s): 926faf6542829ac64325965f18d1ba82 ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - glibc New glibc packages will be available soon which fix a RPC XDR integer overflow. The packages are currently being tested. - vnc VNC (Virtual Network Computing) uses a weak cookie generation process which can be exploited by an attacker to bypass authentication. New packages are currently being tested and will be available on our FTP servers soon. ______________________________________________________________________________ 3) standard appendix: authenticity verification, additional information - Package authenticity verification: SuSE update packages are available on many mirror ftp servers all over the world. While this service is being considered valuable and important to the free and open source software community, many users wish to be sure about the origin of the package and its content before installing the package. There are two verification methods that can be used independently from each other to prove the authenticity of a downloaded file or rpm package: 1) md5sums as provided in the (cryptographically signed) announcement. 2) using the internal gpg signatures of the rpm package. 1) execute the command md5sumafter you downloaded the file from a SuSE ftp server or its mirrors. Then, compare the resulting md5sum with the one that is listed in the announcement. Since the announcement containing the checksums is cryptographically signed (usually using the key security@suse.de), the checksums show proof of the authenticity of the package. We disrecommend to subscribe to security lists which cause the email message containing the announcement to be modified so that the signature does not match after transport through the mailing list software. Downsides: You must be able to verify the authenticity of the announcement in the first place. If RPM packages are being rebuilt and a new version of a package is published on the ftp server, all md5 sums for the files are useless. 2) rpm package signatures provide an easy way to verify the authenticity of an rpm package. Use the command rpm -v --checksig to verify the signature of the package, where is the filename of the rpm package that you have downloaded. Of course, package authenticity verification can only target an un-installed rpm package file. Prerequisites: a) gpg is installed b) The package is signed using a certain key. The public part of this key must be installed by the gpg program in the directory ~/.gnupg/ under the user's home directory who performs the signature verification (usually root). You can import the key that is used by SuSE in rpm packages for SuSE Linux by saving this announcement to a file ("announcement.txt") and running the command (do "su -" to be root): gpg --batch; gpg < announcement.txt | gpg --import SuSE Linux distributions version 7.1 and thereafter install the key "build@suse.de" upon installation or upgrade, provided that the package gpg is installed. The file containing the public key is placed at the top-level directory of the first CD (pubring.gpg) and at . - SuSE runs two security mailing lists to which any interested party may subscribe: suse-security@suse.com - general/linux/SuSE security discussion. All SuSE security announcements are sent to this list. To subscribe, send an email to <suse-security-subscribe@suse.com>. suse-security-announce@suse.com - SuSE's announce-only mailing list. Only SuSE's security announcements are sent to this list. To subscribe, send an email to <suse-security-announce-subscribe@suse.com>. For general information or the frequently asked questions (faq) send mail to: <suse-security-info@suse.com> or <suse-security-faq@suse.com> respectively. ==================================================================== SuSE's security contact is <security@suse.com> or <security@suse.de>. The <security@suse.de> public key is listed below. ====================================================================______________________________________________________________________________ The information in this advisory may be distributed or reproduced, provided that the advisory is not modified in any way. In particular, it is desired that the clear-text signature shows proof of the authenticity of the text. SuSE Linux AG makes no warranties of any kind whatsoever with respect to the information contained in this security advisory. Type Bits/KeyID Date User ID pub 2048R/3D25D3D9 1999-03-06 SuSE Security Team <security@suse.de> pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key <build@suse.de>