-----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SuSE Security Announcement Package: shadow/login Announcement-ID: SuSE-SA:2001:034 Date: Tuesday, Oct 23rd 2001 18:00 MEST Affected SuSE versions: 6.3, 6.4, 7.0, 7.1, 7.2, 7.3 Vulnerability Type: local privilege escalation Severity (1-10): 2 SuSE default package: yes Other affected systems: most linux systems, common problem on linux-like systems. Content of this advisory: 1) security vulnerability resolved: shadow/login problem description, discussion, solution and upgrade information 2) pending vulnerabilities, solutions, workarounds 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information Multiple Linux vendors have issued security announcements about failures of the /bin/login program to properly initialize the privileges of an authenticated user if the PAM module pam_limits is enabled. The bug has been categorized as a sequence bug, and is located in the code of the login program itself: A call to getpwnam(3) returns a pointer to a struct passwd, and the data is being used. Then, a call to PAM routines cause getpwnam(3) to be called again, but beyond the programmer's control or knowledge. The pointer as returned by the first getpwnam(3) remains the same, but the data may be different. By consequence, the data is in an undefined state. The error appears with the pam_limits PAM module only because other PAM modules do not call getpwnam(3). SuSE developers did not succeed in reproducing the error on SuSE Linux installations since SuSE distributions do not come with the standard login implementation from the util-linux collection. Instead, a version maintained by Thorsten Kukuk is used. This login implementation may cause wrong group IDs to be set in very rare cases. The harm of this bug is therefore considerably small on SuSE Linux. However, we provide fixed rpm packages that remedy the problem. Since the bug is not limited to the login program but to all programs that authenticate users, more security announcements in this field are to be expected. The Linux vendors cooperate to share the workload that results from the audit of these programs. To install the updates, please download the update package for your distribution and use the command 'rpm -Uhv file.rpm' to apply the update. Please run "SuSEconfig" after performing the package update to make sure that the permissions of your files are configured as the security settings of your installation define. Alternatively, if you have disabled SuSEconfig, check for the permissions of the files /usr/bin/chage, /usr/bin/chfn, /usr/bin/chsh, /usr/bin/expiry, /usr/bin/gpasswd and /usr/bin/passwd to suit your needs. Setting these executeables to 4755 owned by root enables their functionality, removing the setuid bit (chmod -s) disables it. i386 Intel Platform: SuSE-7.3 ftp://ftp.suse.com/pub/suse/i386/update/7.3/a1/shadow-20000902-144.i386.rpm 9380496a4a248aeac73d7136de381348 source rpm: ftp://ftp.suse.com/pub/suse/i386/update/7.3/zq1/shadow-20000902-144.src.rpm b595cea811bb92aa895974aee2fd5968 SuSE-7.2 ftp://ftp.suse.com/pub/suse/i386/update/7.2/a1/shadow-20000902-145.i386.rpm 18e33d4b728b49403c2679c560b52f06 source rpm: ftp://ftp.suse.com/pub/suse/i386/update/7.2/zq1/shadow-20000902-145.src.rpm 0d9fb9cec79cdd4671306658a103fc6b SuSE-7.1 ftp://ftp.suse.com/pub/suse/i386/update/7.1/a1/shadow-20000902-145.i386.rpm a5b2177d66048f988249e0acbc9648bf source rpm: ftp://ftp.suse.com/pub/suse/i386/update/7.1/zq1/shadow-20000902-145.src.rpm 4525572bf268b73004774a25d7f5de2a SuSE-7.0 ftp://ftp.suse.com/pub/suse/i386/update/7.0/a1/shadow-19990827-170.i386.rpm 2be3765b08ce9d94abbd4932dbe3f39b source rpm: ftp://ftp.suse.com/pub/suse/i386/update/7.0/zq1/shadow-19990827-170.src.rpm 97935450371dde96cb92134ab8596b85 SuSE-6.4 ftp://ftp.suse.com/pub/suse/i386/update/6.4/a1/shadow-19990827-145.i386.rpm c6d07aa8662e00d501f9fbb9d57f71bb source rpm: ftp://ftp.suse.com/pub/suse/i386/update/6.4/zq1/shadow-19990827-145.src.rpm 79d9e99e67fcd23d64508eafe5070b36 SuSE-6.3 ftp://ftp.suse.com/pub/suse/i386/update/6.3/a1/shadow-19990827-145.i386.rpm 82c4466697251685c5f1fa733c0ad4e2 source rpm: ftp://ftp.suse.com/pub/suse/i386/update/6.3/zq1/shadow-19990827-145.src.rpm bac32336670e134146af62886e3d477e Sparc Platform: SuSE-7.1 ftp://ftp.suse.com/pub/suse/sparc/update/7.1/a1/shadow-20000902-92.sparc.rpm 3e63326bd5dd2dd3e9d8175b6db918e0 source rpm: ftp://ftp.suse.com/pub/suse/sparc/update/7.1/zq1/shadow-20000902-92.src.rpm c95b2761cc4d9b417394a550d43716ca SuSE-7.0 ftp://ftp.suse.com/pub/suse/sparc/update/7.0/a1/shadow-19990827-2.sparc.rpm 5ce1d42bb0e5a6677666390b9980de5d source rpm: ftp://ftp.suse.com/pub/suse/sparc/update/7.0/zq1/shadow-19990827-2.src.rpm 622dc8e8c6d6bf90f09d79b144a20533 AXP Alpha Platform: SuSE-7.1 ftp://ftp.suse.com/pub/suse/axp/update/7.1/a1/shadow-20000902-88.alpha.rpm ed882226bcb5241e105fb0f6466bf476 source rpm: ftp://ftp.suse.com/pub/suse/axp/update/7.1/zq1/shadow-20000902-88.src.rpm b70743683ca521d66be357b90baff035 SuSE-7.0 ftp://ftp.suse.com/pub/suse/axp/update/7.0/a1/shadow-19990827-74.alpha.rpm 778ebfcaacc9087e6c781f6a10a68a75 source rpm: ftp://ftp.suse.com/pub/suse/axp/update/7.0/zq1/shadow-19990827-74.src.rpm 68d957bf5d0cc942e12501056d05f0bd SuSE-6.4 ftp://ftp.suse.com/pub/suse/axp/update/6.4/a1/shadow-19990827-74.alpha.rpm e7646c335fa009506535412daf344480 source rpm: ftp://ftp.suse.com/pub/suse/axp/update/6.4/zq1/shadow-19990827-74.src.rpm 3d748914265b37b15b42687e5ff87945 SuSE-6.3 ftp://ftp.suse.com/pub/suse/axp/update/6.3/a1/shadow-19990827-74.alpha.rpm c1cb80bb6d7a15a445550c739ced029b source rpm: ftp://ftp.suse.com/pub/suse/axp/update/6.3/zq1/shadow-19990827-74.src.rpm 0b05d59fffc9ff8bd1cb922df7a84fac PPC Power PC Platform: SuSE-7.1 ftp://ftp.suse.com/pub/suse/ppc/update/7.1/a1/shadow-20000902-61.ppc.rpm a1dbc8bb966db28469fabe583d157bed source rpm: ftp://ftp.suse.com/pub/suse/ppc/update/7.1/zq1/shadow-20000902-61.src.rpm 2b2f0fbcb842149cb095fff125f54279 SuSE-7.0 ftp://ftp.suse.com/pub/suse/ppc/update/7.0/a1/shadow-19990827-182.ppc.rpm d55986fc84158f06dcbfea0c7812037f source rpm: ftp://ftp.suse.com/pub/suse/ppc/update/7.0/zq1/shadow-19990827-182.src.rpm dc84f0301b4a4daeae1fb6465f0d16c1 SuSE-6.4 ftp://ftp.suse.com/pub/suse/ppc/update/6.4/a1/shadow-19990827-182.ppc.rpm 3d7e644c70e6d98944ff623b24bbfde0 source rpm: ftp://ftp.suse.com/pub/suse/ppc/update/6.4/zq1/shadow-19990827-182.src.rpm 646985dc82d9845832db6863fba9442d ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - Linux kernel Security bugs have been found in both the 2.2 and 2.4 kernel series of all currently supported SuSE Linux distributions (6.3-7.3), including the freshly appeared SuSE-7.3. These bugs allow a local attacker to gain root privileges, but there is no remote attack as of now. As a temporary workaround, it is possible for experienced users of linux-like systems to disable all setuid bits from all files in the installed system using a find command with a -exec option. We are currently in the process of testing the update kernels of both 2.2 (2.2.19) and 2.4 (2.4.13) series to make sure that these update kernels will have the same level of stability and robustness as expected from SuSE linux systems. The official kernel rpm packages will be announced in a SuSE Security announcement during the second half of this week. In the meanwhile, the directory ftp://ftp.suse.com/pub/people/mantel/next/ contains the preliminary update packages for testing (2.2.19 packages will be available shortly). Please proceed with the update as described in http://www.suse.de/de/support/security/2001_018_kernel_txt.txt and report any problems that you may find to feedback@suse.de. - openssh After stabilizing the openssh package, updates for the distributions 6.4-7.2 are currently being prepared. The update packages fix a security problem related to the recently discovered problems with source ip based access restrictions in a user's ~/.ssh/authorized_keys2 file. The packages will appear shortly on our ftp servers. Please note that packages for the distributions 6.3 and up including 7.0 containing cryptographic software are located on the German ftp server ftp.suse.de, all other packages can be found on ftp.suse.com at the usual location. - htdig (ht://Dig) htdig, a powerful indexing and information gathering tool for a webserver, has been found vulnerable to a weakness where commandline options can be passed on to the cgi program as a result of weak runtime environment checking. The security announcement by Thomas Biege is waiting for the update packages to reach the ftp-server (currently transferring). Please continue to watch the suse-security-announce mailing list for new security announcements. ______________________________________________________________________________ 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 md5sum after 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 uninstalled 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 toplevel directory of the first CD (pubring.gpg) and at ftp://ftp.suse.com/pub/suse/pubring.gpg-build.suse.de . - 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-announce@suse.com - SuSE's announce-only mailing list. Only SuSE's security annoucements are sent to this list. To subscribe, send an email to . For general information or the frequently asked questions (faq) send mail to: or respectively. =================================================== SuSE's security contact is . The 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 cleartext signature shows proof of the authenticity of the text. SuSE GmbH 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 pub 1024D/9C800ACA 2000-10-19 SuSE Package Signing Key - -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org mQENAzbhLQQAAAEIAKAkXHe0lWRBXLpn38hMHy03F0I4Sszmoc8aaKJrhfhyMlOA BqvklPLE2f9UrI4Xc860gH79ZREwAgPt0pi6+SleNFLNcNFAuuHMLQOOsaMFatbz JR9i4m/lf6q929YROu5zB48rBAlcfTm+IBbijaEdnqpwGib45wE/Cfy6FAttBHQh 1Kp+r/jPbf1mYAvljUfHKuvbg8t2EIQz/5yGp+n5trn9pElfQO2cRBq8LFpf1l+U P7EKjFmlOq+Gs/fF98/dP3DfniSd78LQPq5vp8RL8nr/o2i7jkAQ33m4f1wOBWd+ cZovrKXYlXiR+Bf7m2hpZo+/sAzhd7LmAD0l09kABRG0JVN1U0UgU2VjdXJpdHkg VGVhbSA8c2VjdXJpdHlAc3VzZS5kZT6JARUDBRA24S1H5Fiyh7HKPEUBAVcOB/9b yHYji1/+4Xc2GhvXK0FSJN0MGgeXgW47yxDL7gmR4mNgjlIOUHZj0PEpVjWepOJ7 tQS3L9oP6cpj1Fj/XxuLbkp5VCQ61hpt54coQAvYrnT9rtWEGN+xmwejT1WmYmDJ xG+EGBXKr+XP69oIUl1E2JO3rXeklulgjqRKos4cdXKgyjWZ7CP9V9daRXDtje63 Om8gwSdU/nCvhdRIWp/Vwbf7Ia8iZr9OJ5YuQl0DBG4qmGDDrvImgPAFkYFzwlqo choXFQ9y0YVCV41DnR+GYhwl2qBd81T8aXhihEGPIgaw3g8gd8B5o6mPVgl+nJqI BkEYGBusiag2pS6qwznZiQEVAwUQNuEtBHey5gA9JdPZAQFtOAf+KVh939b0J94u v/kpg4xs1LthlhquhbHcKNoVTNspugiC3qMPyvSX4XcBr2PC0cVkS4Z9PY9iCfT+ x9WM96g39dAF+le2CCx7XISk9XXJ4ApEy5g4AuK7NYgAJd39PPbERgWnxjxir9g0 Ix30dS30bW39D+3NPU5Ho9TD/B7UDFvYT5AWHl3MGwo3a1RhTs6sfgL7yQ3U+mvq MkTExZb5mfN1FeaYKMopoI4VpzNVeGxQWIz67VjJHVyUlF20ekOz4kWVgsxkc8G2 saqZd6yv2EwqYTi8BDAduweP33KrQc4KDDommQNDOXxaKOeCoESIdM4p7Esdjq1o L0oixF12CpkBogQ57vSBEQQAk/GN+ftr7+DBlSoixDDpfRnUk+jApGEt8hCnrnjV nPs/9Cr33+CXLQbILOO7Y5oiPbJdHh45t4E0fKyLVzDerCRFB1swz/mNDxT26DLy sdBV5fwNHTPhxa67goAZVrehQPqJEckkIpYriOaYcKpF3n5fQIZMEfMaHEElQhcX ML8AoJVXDkJYh7vI8EUB8ZURNLZMEECNA/sH0MCnb4Q6ZcRyeZ3+1PHP8hP73b6T epRdLZhaylwVF/iu7uIn62ZUL4//NTOCDY7V63qg4iba/fUbOsWtEnGaiE7mQuAl sSWvRspwRA9/g9rdVf3/JdLJrLmKBTheyG+PSJE3W7cAE4ZWafGxIRCwXhmj3TQn Jn2euqylHRubEQP/aL53NZK0kBdvrKgff6O8Of6tqoss8Dkk55I7QVFSp+My1Dn+ mngQKFejTAgtyo/WmR3wPjQ9HoT2lRiYI2lTRYT4uMdHuwVC3b4DqAKmoy375FER wHkrMVyKBJslv8QtbAWw5A1CAUseaHo+91wmYJ4/4p6YUahqbG/tZyhbxfq0KFN1 U0UgUGFja2FnZSBTaWduaW5nIEtleSA8YnVpbGRAc3VzZS5kZT6IXAQTEQIAHAUC Oe70gQUJA8JnAAQLCgMEAxUDAgMWAgECF4AACgkQqE7a6JyACspfLACffAYA+NM8 NBhyRyH+nTX58CNjwLIAoIx9fj52BJe0xY7WbKoXs1+72b2AiEYEEBECAAYFAjpw XlIACgkQnkDjEAAKq6TczgCgi+ddhWb7+FWcfeE6WwPZccqAHowAnjjtRyGwHLQH r5OTFAYTXi2Wv6jNiQEVAwUQOnBgb3ey5gA9JdPZAQE1pwf/QJ+b34lFBNVUJ7fk /xGJJREt7V12iSafaRzGuH8xWvIz1bb+VARxnnt16FDQ1cDNjoEhCEmcW83Vxp6i JXE9PE8wVA/Yue/bon5JS7J69+UiQ2eq2pudfwljp52lYVM53jgPYEz0q/v3091n lZ8CYkAkN9JDS1lV1gEzJ7J0+POngDpU+lDQT2EC6VKaxeWK8pNt6UFDwICRDQxK nlOoiDvTrdWT7QdJZ4sPv8Qotdw9+tKNbWQ2DqdIRxyTdw9xDfAtcj6mXeQr7852 Lwem1gSKVnEYHZ9g1FTJqVOutY8KhpUc9RfOCRv8XuIxrs4KSbfSF0s8qIRCQelx ufg9AbkCDQQ57vSSEAgAhJHQTejMX+Vr6g1pHDEcusJ63fQ2CfFFE5iE9okH9O7U VCiSfb9CV38dmeHdPCEEjDUWquFYEnvj3WICMtH249t1Ymuf4Du3yRKQ9oXdn/qT Jzlrx9qzjiG3mH7ocwHOgUIwCrZoEdBEVE2n0zPVm+hddwjWWTWXw6pxQz+i9dsN 89xexRV5M9O0bNwCLaNWX2GXeLAkqTK/9EuZy6x2yLxi6du9YYUAXkZpqBhCjtiU XpRoFCdglMznbcAyCk9C2wqb2j/D1Z2BeSBaGCSFkR6pRLebnE17LWcu72Iy+r0z +JecbPiyDpDZj4apn7IC81aNFGi7fNITsHODbwwjiwADBgf/YPvVdzkc8OC7ztac EWCanwylKvxCdKzTDA+DfES6WUYShyiVJvZzRy25LJ5WcK20kzOS6Qv1OrIXiz/p dGy1aKtJZrAnFEsofpmOj8VoqyyFgp/yAGQBp12+mXek7SCZRhuqalDfEMRiWEJ6 J5dLkyShyRDWyPbFh0HXE7QTHN+IKKxxQqNQXL6Z3NSxS61p+5n6BseiDUI39xxk KTFwFrkgUIc5Gs2Or2lhaWvGwSfoCmwbsklszZt6xbU+R0SjFqTvjPWx6eHfqbmN C9WMDdTjGrXDDKXFp2aYlokfN6It9vsbVlGNlOwHt/JjGoPMxW6Xqj0FLA7/Vewg CdXW64hMBBgRAgAMBQI57vSSBQkDwmcAAAoJEKhO2uicgArKSyIAmwUHf/vtKQfc mVg4asR7U6XQl0bAAJ4pO22B5U8UH6IYl2LBCXFqw5+5fA== =rVRn - -----END PGP PUBLIC KEY BLOCK----- -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv iQEVAwUBO9WaOXey5gA9JdPZAQFRVgf/Q7zvHx1SKSCitzYdZQooGzusMXsKYAK7 9SKLql13Bzv0DKSMAUfhjbyjQ/jN9DSMLzFNUT4k1AYoN6rxcHEpGvGq+dvBI1ka uDuuO0gMOofsQYHbCK3jxMpCpmPv2i5DUKmTr3JTQ4CL+4a/AiwmoGJjv3S39YFN OEe2B3b0rU/3rv04HSR70SNtzNd7hyrLnJu/f9FkaNTJbq+AIsz76uXHBhg2xfuo Niq6DaozXvJh9eg/0NgsxtXYgQk1XIUHrWgSdChq4n2NbTI/ZOJB1Jwsd8819OLy dKE4vIP+Ou3u8RqIP/pjf21REqqhezPtSavpLX6+36OyzaskmyG11w== =k7ul -----END PGP SIGNATURE-----