November 2000 - openSUSE Security - openSUSE Mailing Lists

SSH Authentication
by Joao Reis 18 Nov '02

18 Nov '02

Hi! I implemented a ssh conection from the outside to my intranet. This ssh requires a username and a password. In terms of security what is more secure: require authentication (username and password) or having the public key of each user that connects to our intranet in the authorized public key lists (in this case there is no need for username and password)? In the second case there is no need of authentication and only the users wich have the public keys in the list are allowed to enter in my intranet. This second solution is a good solution or that brings other security problems ? Thanks. -- Farewell. "Keep your friends close, but your enemies closer." "Do or do not. There is no try" - Yoda João Reis -------------------------------------------------------

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Re: is SuSE going to implement libsafe?
by marc＠suse.de 18 Feb '01

18 Feb '01

Hi, >I have just read an Bell Labs anouncement, that they are going to release >libsafe under GNU licence, and that some major Linux distros are going to >be using it. SuSE was not amongst them, why is that? I think that libsafe would >be a good echnacement against buffer overflow. > >Anouncement is on: >http://www.bell-labs.com/news/2000/april/20/1.html just because something new pops up please be careful with questions like "when will you implement it?" ;-) There are several questions to ask: a) is it STABLE and does it NOT affect the stability of other programs? b) does it bring additional security problems into the system? c) is the security protection effective? Well, of course the SuSE Security Team already reviewed libsafe. Here are the answers: a) unsure. it would have to be tested very intensive. this was not done yet. b) the code might have vulnerabilities, however the protection gained is higher even if a vulnerability would be present c) okay, now the tough part: libsafe is a dynamic library which is set in the environment which checks several dangerous functions, which can be a security problem. Because it is a dynamic library, it is NO protection against local attackers, just against remote attackers on network services. (if an attacker wants to attack a local suid file, he would just reset his library path environment). Next thing: it does not check for all known vulnerabilites. It even doesn't protect against all buffer overflows, It just protects against *some* overflows. those which happen because of insecure use of strcat/strcpy etc. summary: I can not remember a vulnerability in a network service for the last year which this tool would have prevented. Therefore: as long as this tool is not enhanced to also protect open/fopen calls against symlink/hardlink/pipe attacks, several more buffer overflow types, system/exec* function protection etc. it is not useful to use this tool. I would rather propose to use the secumod module which comes with SuSE Linux since 6.3 and maybe the secure-linux kernel patch from www.openwall.com - these two tools enhance your security. (and btw, install seccheck, hardensuse and firewals and use them - then your security is very high) Greets, Marc -- Marc Heuse, SuSE GmbH, Schanzaeckerstr. 10, 90443 Nuernberg E@mail: marc(a)suse.de Function: Security Support & Auditing "lynx -source http://www.suse.de/~marc/marc.pgp | pgp -fka" Key fingerprint = B5 07 B6 4E 9C EF 27 EE 16 D9 70 D4 87 B5 63 6C

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telnet as a root on a suse 6.3 suse server
by Francesco Masiello 02 Jan '01

02 Jan '01

I must be able to telnet from a terminal (not a console) as a root without using su. In solaris i could do that editing /etc/default/login file,but i can't find it on this Operating System. How can i do ? Thanks

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SuSE Security Announcement: netscape (SuSE-SA:2000:48)
by Roman Drahtmueller 13 Dec '00

13 Dec '00

-----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SuSE Security Announcement Package: netscape Announcement-ID: SuSE-SA:2000:48 Date: Thursday, November 30th, 2000 19:00 MET Affected SuSE versions: 6.0, 6.1, 6.2, 6.3, 6.4, 7.0 Vulnerability Type: clientside remote vulnerability Severity (1-10): 4 SuSE default package: yes Other affected systems: systems w/ netscape versions before 4.76 Content of this advisory: 1) security vulnerability resolved: netscape 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 Michal Zalewski <lcamtuf(a)DIONE.IDS.PL> has found a buffer overflow in the html parser code of the Netscape Navigator in all versions before and including 4.75. html code of the form <form action=foo method=bar> <input type=password value=long string here> more form tags </form> can crash the browser. It may be possible for an attacker to supply a webpage that executes arbitrary code as the user running netscape. As of today, no exploit code is known to exist in the wild. SuSE provides an update package for the vulnerable software. It is recommended to upgrade to the latest version found on our ftp server as described below. The update package introduces Netscape version 4.76. NOTE: Please note that Netscape-4.76 is not available for the glibc-2.0-based SuSE Distributions SuSE-6.0 and 6.1 because Netscape doesn't provide any binaries for the glibc version in these distributions (glibc-2.0). For SuSE-6.0 and 6.1, we provide a libc5-based version of netscape-4.76 which runs smoothly on all i386-based SuSE distributions 6.x and 7.x, provided the package shlibs5 is installed. The package can be found in the update/5.3 directory on our ftp server (see below). There are no packages available for platforms other than i386. NOTE: The packages on our ftp servers date back to October 31st. Since there is no release notes or README file with equivalent content in the netscape tarball, SuSE security was not aware of the fact that this release of netscape fixes the known problems. This information can be obtained from (along with information about other bugfixes) http://home.netscape.com/eng/mozilla/4.7/relnotes/windows-4.76.html . Please choose the update package(s) for your distribution from the URLs listed below and download the necessary rpm files. Then, install the package using the command `rpm -Uhv file.rpm´. rpm packages have an internal md5 checksum that protects against file corruption. You can verify this checksum using the command (independently from the md5 signatures below) `rpm --checksig --nogpg file.rpm', The md5 sums under each package are to prove the package authenticity, independently from the md5 checksums in the rpm package format. Intel i386 Platform SuSE-7.0 SuSE-6.4 SuSE-6.3 SuSE-6.2 ftp://ftp.suse.com/pub/suse/i386/update/7.0/xap1/netscape-4.76.glibc21.i386… 7ccebaca7df0937a3c08fc30a27af858 SuSE-6.1 SuSE-6.0 ftp://ftp.suse.com/pub/suse/i386/update/5.3/xap1/netscape-4.76.libc5.i386.r… 3c4f06c5fea4755083524eb135627380 ______________________________________________________________________________ 2) Pending vulnerabilities in SuSE Distributions and Workarounds: - ssh/openssh Several inconsistencies and configuration bugs have been introduced in the SuSE rpm packages for the update of openssh (SuSE-SA:2000:47) that cause the openssh software to not work as reliably as usual. The packages are about to be reworked, the openssh announcement will be reissued. - pidentd The in.identd daemon on SuSE distributions can be crashed remotely. We're working on a fix. - bash1 bash, version 1, handles temporary files in an unsafe manner that allows a local attacker to overwrite arbitrary files as the user running a bash1 with input redirection of the "<< EOF" style. The bash1 package is not used per default in SuSE-distributions. We're working on a fix (update packages). - tcsh The paragraph above about bash version 1 applies to the tcsh as well, in all versions. The tcsh is not used by SuSE scripts. ______________________________________________________________________________ 3) standard appendix: SuSE runs two security mailing lists to which any interested party may subscribe: suse-security(a)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(a)suse.com>. suse-security-announce(a)suse.com - SuSE's announce-only mailing list. Only SuSE's security annoucements are sent to this list. To subscribe, send an email to <suse-security-announce-subscribe(a)suse.com>. For general information or the frequently asked questions (faq) send mail to: <suse-security-info(a)suse.com> or <suse-security-faq(a)suse.com> respectively. =============================================== SuSE's security contact is <security(a)suse.com>. =============================================== Regards, Roman Drahtmüller. - - -- - - | Roman Drahtmüller <draht(a)suse.de> // "Caution: Cape does | SuSE GmbH - Security Phone: // not enable user to fly." | Nürnberg, Germany +49-911-740530 // (Batman Costume warning label) | - - ______________________________________________________________________________ The information in this advisory may be distributed or reproduced, provided that the advisory is not modified in any way. SuSE GmbH makes no warranties of any kind whatsoever with respect to the information contained in this security advisory. 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Linux 7.0
by C.Richartz＠wzl.rwth-aachen.de 13 Dec '00

13 Dec '00

Hi, my name is Chris and I just started using LINUX. Now my problem I have to install a very save server. The server should work as a file-server which is also WWW-router, firewall and Mailserver for a network of 25 workstations with Windows NT. 5 Days ago I started working in LINUX but my employer wants me to create a server that is saver than a very save NT-system. I'm not able to create such a system by myself!! Please Help me Greetings Chris

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RPM-Update on all boxes in a LAN
by gtschakert＠gmx.de 05 Dec '00

05 Dec '00

Hi, after reading the last security-announcement I ask myself if there is a tool to update the new rpm automatically to all the boxes in my LAN. What I want to do is the following: I recieve the security-announcement: I decide to install or not and download the rpm. I start a script, which will install the rpm to the boxes of my choice. I don't want to login on every box, install the rpm and go to the next box. I hoped alice would do things like that, but I think alice is only a tool for new installation (and you have to make a floopy-disk or a CD). And I think, some month ago, I have read about a scripting-language for system administrators, but I don't remember where. Anybody, who can help me.

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Re: [suse-security] Re: password files for proftp
by Max Lindner 03 Dec '00

03 Dec '00

Hello Thom Am Don, 30 Nov 2000 schrieb Thorsten Marquardt: > Hello Magus > > Am 30-Nov-00 schrieb Magus Ba'al: > > > I got this from http://www.proftpd.net/docs/complex-virtual.conf > > > > AuthUserFile /where.ever.you.want.to.stick.it > > AuthGroupFile /where.ever.you.want.to.stick.it > > > > What _I_ prefer to do is create a directory, let's call it /var/domains. > > Because I host multiple domains, I put the auth files in /var/domains with > > the name , and then create a dir in /var/domain/(domain name). It keeps it > > neat and tidy for me if I ever need to find anything related to the > > domain. > > so far so good. But I don't know how to create the AuthUserFile itself. > why don't you use the program 'htpasswd', afaik it's delivered with apache. htpasswd makes a file with a username&password-File. this files contains in each line one user. It's build like the /etc/passwd: username:passwd:uid:gid:comments:Home-dir:shell but with htpasswd, you've only the 1st and 2nd entry, the others have to be edited by you. that's the way I do it... Max

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Ftp Services disabled
by Pao Sayaovang 01 Dec '00

01 Dec '00

Hello: Im a newbie at Linux. Recently setup a SuSE 7.0 LinUx box and had everything going well. Until, I made a few changes in the /etc/rc.config and somehow disabled my FTP Services. I've also made changes in my etc/rc.config.d/firewall.rc.config too and now I totally blocked out of my ftp services. I know I'm not being clear on the info I've given but can anyone help me get started with re-enabling ftp services again. Is it? start Inetd="yes"?? start Proftpd="yes"???? Thanks, ___________________________ Pao Sayaovang Weyco Group, Inc DID(414) 908~1813 Fax(414) 908~1913 psayang(a)weycogroup.com

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SuSE Linux 6.x 7.0 Ident buffer overflow
by Rash 01 Dec '00

01 Dec '00

http://linuxtoday.com/news_story.php3?ltsn=2000-11-28-024-04-SC-SS Has anybody exploit for this subj? I wanna check myself and my friends :-)

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any nntp proxy ?
by Olivier Hislaire 30 Nov '00

30 Nov '00

Hi, I need to install a nntp proxy on my suse 6.3, and I tried acmennrp. When I start it, it justs stops without a single (error) message; I bet there is something missing. Since I cannot read java (sorry),and cannot find a clue of a documentation neither any logged message anywhere (yes, syslogd is configured and working all right), what else can I do ? Does anybody knows about using acmennrp (proxy mode only), or any other SW that woul do it ? Thanks, Olivier. ------------------------------------------------------------------------------------------------ Olivier Hislaire MSG International Email: O.Hislaire(a)msg-i.com 97 Avenue de Tervuren Phone: +32 (0)2 735.91.59 Ext. 55 1040 Brussels Fax: +32 (0)2 732.12.19 Belgium http://www.msg-i.com ------------------------------------------------------------------------------------------------

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