August 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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Netscape update RPM and axp
by Stefan Suurmeijer 13 Sep '00

13 Sep '00

Hi SuSE I need to update a few servers running SuSE 6.3 for AXP. I wanted to update the old netscape version, but noticed there is no rpm available under the AXP directory (for any version). Is there an RPM available for Alpha, or do I need to update all servers manually? Stefan ========================================== Stefan Suurmeijer Network Specialist University of Groningen tel: (+31) 50 363 3423 fax: (+31) 50 363 7272 E-mail (business): s.m.suurmeijer(a)let.rug.nl E-mail (private): stefan(a)symbolica.nl ========================================== Quis custodiet ipsos custodes? (Who'll watch the watchmen?) - Unknown

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sparc
by semat＠wawa.eahd.or.ug 05 Sep '00

05 Sep '00

Hello everyone, Please I realise this is off topic so please address your answers to me off list. Is there suse linux for sparc platform? I have a sparc box and suse is really my preferred distro so if it supports it I will be very happy to get it. Otherwise I have to use redhat.

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AW: [suse-security] Popper verbosity
by Klug, Boris 04 Sep '00

04 Sep '00

Hi! this does NOT work. You have to uncomment the output lines in the popper code and recompile it. -- i.A. Dipl.-Inf. Boris Klug, boris.klug(a)ibs-ag.de, http://www.ibs-ag.de/ IBS AG engineering consulting software, The Quality Company Rathausstraße 56, 56203 Höhr-Grenzhausen, Fon: 02624/9180-0, Fax: -200 > -----Ursprüngliche Nachricht----- > Von: Roman Drahtmueller [mailto:draht@suse.de] > Gesendet: Montag, 21. August 2000 14:30 > An: Jürgen Bloß > Cc: suse-security(a)suse.com > Betreff: Re: [suse-security] Popper verbosity > > > > Hi. > > > > How can I stop the popper from logging every user access, > even when the > > user did only check to see if there were any new mails. This seems > > hardly the kind of information that needs to be logged every time... > > > > Bye, > > > > Jürgen > > According to the manpage, just remove the "-s" from the line in > /etc/inetd.conf and restart/hangup inetd. > > Roman. > -- > - > - > | 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) | > - > - > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: suse-security-unsubscribe(a)suse.com > For additional commands, e-mail: suse-security-help(a)suse.com >

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Total system update
by RoMaN SoFt / LLFB !! 04 Sep '00

04 Sep '00

Hi SuSE: I have recently installed 6.4 version and I want to secure my machine. Is there any way for *auto*-updating *all* (installed) RPM's via SuSE web? Which URL should I use to get the more recent Updates for my distro? I think this is a FAQ, I have RTFM... but I want no silly mistakes, so I prefer asking here and get always updated info :-) Thanks folks! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= ** RoMaN SoFt / LLFB ** roman(a)madrid.com http://bart.us.es/~roman ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Book wanted: Linux security
by Roman Blöth 04 Sep '00

04 Sep '00

Dear reader, I'm looking for a _good_ book on linux system security (something like one of these "hacker guides"). If you could recommend a book your answer would greatly be appreciated. Best regards, Roman Blöth. -- gosub communications GbR | Fredersdorferstr. 10 | 10243 Berlin | Germany phone: [+49] (-30) 29 66 88 81 | fax: [+49] (-30) 29 66 88 84 | http://www.gosub.de

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SuSE distro bundled crypto
by Corvin Russell 31 Aug '00

31 Aug '00

No feedback from feedback(a)suse.de... so here goes. Will SuSE be shipping the full sec series, as bundled in the German/UK versions, with the US version? Aside from the fact that AFAIK it was never illegal to import crypto, patent considerations aside (and September is nigh...), into the US, and that therefore SuSE should have been able to bundle the same sec series all along, the US has recently relaxed crypto regulations. Meanwhile we here in Canada have never had them, nor do US laws apply to crypto exported to Canada, but still we had to get the crippled US distribution (yes, to answer a previous question, there is a US distribution), thus defeating the purpose of getting the software on relatively secure, easily rebooted pristine media, and forcing us to spend unnecessary time searching and downloading stuff. After I grumbled, SuSE GMBH kindly shipped me a free UK version on a one-time only basis, but they won't do that again, for me or anyone, I am sure. So, will SuSE 7.0 US edition ship with security or not? If not, please say so on the package and the website. And BTW, FreeBSD 4.0 shipped with all the crypto packages bundled. There is some lame question about whether you live in the US/Canada or not, but otherwise they are all there and as far as I can tell there is nothing to stop you from lying, and no one at FreeBSD seems to have gotten in trouble. Best, Corvin

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migrating user database from SuSE 6.4 to 7.0
by jan meyer 31 Aug '00

31 Aug '00

Hi, I would like to migrate the user database (50 users) from my SuSE 6.4 Server to SuSE 7.0. I'm using the default SuSE password mechanism. Does anybody know some hints, tips, links or tools on how to do this ? Thanks jan.meyer

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SuSE Security Announcement: Netscape
by Roman Drahtmueller 31 Aug '00

31 Aug '00

-----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SuSE Security Announcement Package: Netscape, Versions 4.x, possibly others Date: Wednesday, August 23rd, 2000 03:30 MEST Affected SuSE versions: All Vulnerability Type: remote file viewing, remote buffer overflow Severity (1-10): 4, 7 SuSE default package: yes Other affected systems: all linux systems using this package Content of this advisory: 1) security vulnerability resolved: Netscape problem description, discussion, solution and upgrade information 2) Correction/apology for perl thread, pending vulnerabilities, temporary workarounds 3) standard appendix (further information) ______________________________________________________________________________ 1) problem description, brief discussion, solution, upgrade information Two security problems exist in the netscape package as shipped with SuSE Linux distributions. a) Improper verification in Netscape's jpeg processing code can lead to a buffer overflow where data read from the network can overwrite memory. As a result, arbitrary code from a remote origin could be executed. The attack is particularly dangerous since it can penetrate firewall setups. Netscape version 4.74 fixes (fixed) this vulnerability. b) Due to an error in the java implementation in Netscape, it is possible for an attacker to view files and directories with the priviledges of the user running Netscape if the user visits a malisciously crafted webpage. This issue is known as "Brown Orifice" and requires the user to have Java enabled in her browser configuration. Again, this attack can penetrate firewall setups. See http://www.brumleve.com/BrownOrifice for details. Problem a) can be circumvented by disabling the automatic image loading in Netscape's configuration. The temporary workaround for problem b) is to disable Java in Netscape's configuration menu (to protect against other vulnerabilities, disable JavaScript, too!). Both countermeasures may widely be found inacceptable. SuSE provides an updated package for the vulnerable software. It is strongly recommended to upgrade to the latest version found on our ftp server as described below. The update package introduces Netscape version 4.75, including the SuSE-specific libraries that fix some of Netscape's "irregular" behaviour. Please note that Netscape-4.75 is not available for the glibc-2.0-based SuSE Distributions SuSE-6.0 and 6.1 because Netscape doesn't provide any files for this glibc version. For these distributions, we provide Netscape Version 4.74 which fixes problem a) only. Alternatively, the package for the libc5-based SuSE-5.3 distribution can be used as well if the package 'shlibs5' is installed. This is recommended, since the 5.3 package may be faster and more reliable. Download the update package as described below and install the package with the command `rpm -Fhv file.rpm'. The md5sum for each file is in the line below. You can verify the integrity of the rpm files using the command `rpm --checksig --nogpg file.rpm', independently from the md5 signatures below. Due to US-American export restrictions for cryptographical software, we are unable to provide update packages on our US ftp server ftp.suse.com. Instead, the packages can be found on ftp.suse.de. For bandwidth reasons, please use our mirrors or our primary mirror ftp.gwdg.de and follow the directory to your distribution. Example: For SuSE-6.4 use the path ftp://ftp.gwdg.de/pub/linux/suse/6.4_update_de/xap1/netscape.rpm. *********************************************************************** Please note that the path to netscape.rpm in the 6.0 and 6.1 update directories point to Netscape version 4.74 which doesn't fix problem b! See section above! *********************************************************************** Further mirrors can be found at http://www.suse.de/de/support/download/ftp/inland.html, but be advised that not all sites mirror the German part of the update directories. md5sums for the i386 Intel Platform (the only one supported): SuSE Versions 6.2, 6.3, 6.4, 7.0: 70289f88b4c9fc1a9867ba7dac985982 netscape-4.75.glibc21.i386.rpm SuSE Version 5.3 (libc5-based, probably faster, can be used on glibc2-based systems if the package shlibs5 is installed) 679aaf67592244a07733bdabdab67729 netscape-4.75.libc5.i386.rpm SuSE Version 6.0 and 6.1, Netscape-4.74 with incomplete fixes: 4bcc31fe37f7c8d226b437c1daa9b944 netscape-4.74.glibc20.i386.rpm ______________________________________________________________________________ 2) Correction/Apology: In my posting to suse-security(a)suse.de and to bugtraq(a)securityfocus.com about the suidperl thread, Subject: "SuSE Security Announcement: suidperl (perl)", dated 10 Aug 2000, I wrote: "A maliciously implemented feature causes the interpreter to spawn the /bin/mail program to"..." This is a bad and embarrassing mistake because of a confusion about the word "maliciously" in this context - it was meant to read "inconsiderate". I apologize to the perl folks for this mistake. Pending vulnerabilities in SuSE Distributions and Workarounds: This section addresses currently known vulnerabilities in Linux/Unix systems that have not been resolved yet as of the release date of this advisory. - ntop ntop is a network statistics visualization utility which offers graphical analysis of network traffic and other statistics with a web browser. By default, ntop listens on port 3000 and requires no or a commonly known authentication password to view the data. ntop is only installed in network server selections and is not activated by default in SuSE Linux installations. The ntop packages shipped with SuSE Linux did not exhibit the unsafe behaviour when a file like /../../etc/passwd is referenced. However, Thomas Biege has reviewed the source of the package and there are still some potential problems with the package that require a major overhaul of the code. Currently, we recommend to disable or even remove the ntop package (`rpm -e ntop') in an environment where security considerations play a role. More information on ntop can be found in ntop's documentation directory /usr/doc/packages/ntop or /usr/share/doc/packages/ntop for SuSE-7.0. - zope SuSE distributions before 7.0 do not contain zope as a package. An updated package for the freshly released SuSE-7.0 is on the way. - xchat A fix for the URL handler vulnerabilty is in progress and will be released within a few days. There is currently no effective and easy workaround other than removing the package by hand (`rpm -e xchat'). More information on xchat can be found in xchat's documentation directory /usr/doc/packages/xchat or /usr/share/doc/packages/xchat for SuSE-7.0. - minicom SuSE's minicom doesn't exhibit the problem with files created belonging to group uucp because /usr/bin/minicom isn't installed sgid uucp by default. Changing this to 2755 root.uucp (manually and in /etc/permissions) doesn't show any defective behaviour either. - xlockmore: After a review of the relevant part of xlock's code we've found that the format string parsing bug posted by bind(a)SUBTERRAIN.NET on bugtraq on August 15th 2000 is not critical wrt security. xlock drops all privs as soon as it could get hold of the user's encrypted password (which is before it crashes). Other encrypted passwords can't be found in xlock's memory. Since xlock on SuSE distributions runs sgid shadow, it can't dump a core file upon segmentation fault (search /usr/src/linux/kernel/sys.c for "dumpable".) and also can't be traced (/usr/src/linux/arch/i386/kernel/ptrace.c). The bug will be fixed in future releases of the SuSE Linux distribution. The following packages are not contained in SuSE distributions. Therefore, they do not impose any security risks on SuSE systems unless an administrator installed (compiled) the vulnerable software by hand. - FlagShip permissions, from Narrow <nss(a)privacyx.com> on bugtraq dated 10 Aug 2000 - VariCAD permissions with RedHat 6.0, from Narrow <nss(a)privacyx.com> on bugtraq dated 10 Aug 2000 - usermode, from Connectiva on bugtraq, dated 2000-08-10 - gopherd 2.x, from Mike Schiffman <michael.schiffman(a)guardent.com> (guardent) on bugtraq, dated 10 Aug 2000, + Chris Sharp <v9(a)FAKEHALO.ORG> on bugtraq dated 20 Aug 2000. - diskcheck perl script, Connectiva sec. adv. on bugtraq dated 2000-08-10 - Statistics Server 5.02x, overflow, from |Zan <izan(a)DEEPZONE.ORG> on bugtraq, dated 10 Aug 2000 - Helix GNOME Updater (helix-update), versions 0.1 through 0.5, from HELIX CODE, INC., on bugtraq, dated 20 Aug 2000 - Darxite overflows, from Guido Bakker <guidob(a)MAINNET.NL> on bugtraq, dated 21 Aug 2000 - Gnome-Lokkit ports left exposed, from Alan Cox <alan(a)LXORGUK.UKUU.ORG.UK> on bugtraq dated 19 Aug 2000 ______________________________________________________________________________ 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. Type Bits/KeyID Date User ID pub 2048/3D25D3D9 1999/03/06 SuSE Security Team <security(a)suse.de> - -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6.3i 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 L0oixF12Cg== =pIeS - -----END PGP PUBLIC KEY BLOCK----- -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv iQEVAwUBOaMtk3ey5gA9JdPZAQECJAf/eWj7H2yFpHj2Rl812BmXD26brkI7wKCR NoxhboH2XcHxxOLK2A1gmFjde5lm9g7iatdytOLYiczz0QqigLgMkqeXGGRxmL6a ODWM+qdHOzIJ+f6G+DsECtYiH+Ez7O1tkuXfFxhW0457dp6o4Vngs2ykF5ITX3Af i0F9KJwb7P7ZNyhQ+q8jwLpts58cCAoyAASVy3vRzGNYFggoj4reXf82Bo+cbYpE +0jd9UpBtkVUACWdf3HaXcVaq7SyVnuNAsXIbSz/5XvH54WJLggmUV0sn+siy/lF gIe/68wtuAJI27LeDcIrskzxFBNs4L5+/QmDqGI1slIM+CtrWbRPBw== =t7fJ -----END PGP SIGNATURE-----

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port 8
by Russell Evans 31 Aug '00

31 Aug '00

I am running the firewall update for SuSE 6.4 with the following settings. FW_DEV_WORLD="eth0" FW_DEV_INT="" FW_DEV_DMZ="" FW_ROUTE="no" FW_MASQUERADE="no" FW_MASQ_NETS="" FW_MASQ_DEV="$FW_DEV_WORLD" FW_PROTECT_FROM_INTERNAL="yes" FW_AUTOPROTECT_GLOBAL_SERVICES="yes" FW_SERVICES_EXTERNAL_TCP="22 53 110 25" FW_SERVICES_EXTERNAL_UDP="514 53" FW_SERVICES_DMZ_TCP="" FW_SERVICES_DMZ_UDP="" FW_SERVICES_INTERNAL_TCP="" FW_SERVICES_INTERNAL_UDP="" FW_TRUSTED_NETS="" FW_SERVICES_TRUSTED_TCP="" FW_SERVICES_TRUSTED_UDP="" FW_ALLOW_INCOMING_HIGHPORTS_TCP="dns" FW_ALLOW_INCOMING_HIGHPORTS_UDP="yes" FW_SERVICE_DNS="yes" FW_SERVICE_DHCLIENT="no" FW_SERVICE_DHCPD="no" FW_FORWARD_TCP="" FW_FORWARD_UDP="" FW_REDIRECT_TCP="" FW_REDIRECT_UDP="" FW_LOG_DENY_CRIT="yes" FW_LOG_DENY_ALL="yes" FW_LOG_ACCEPT_CRIT="yes" FW_LOG_ACCEPT_ALL="no" FW_KERNEL_SECURITY="yes" FW_STOP_KEEP_ROUTING_STATE="no" FW_ALLOW_PING_FW="yes" FW_ALLOW_PING_DMZ="no" FW_ALLOW_FW_TRACEROUTE="no" FW_ALLOW_FW_SOURCEQUENCH="yes" FW_MASQ_MODULES="autofw cuseeme ftp irc mfw portfw quake raudio user vdolive" The following was logged. My hostname and IP changed. Aug 27 20:06:14 noname kernel: Packet log: input ACCEPT eth0 PROTO=1 24.8.72.245:8 xxx.yyy.zzz.www:0 L=36 S=0x00 I=56281 F=0x0000 T=118 (#6) Is this a hole in the firewall setup? I do not have the experience to know. Thank you Russell

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bootscreen
by Peter ten Have 30 Aug '00

30 Aug '00

Hello all, However not directly a security (only sniffing) question maybe you've an answer ready. My Linux box is acting as a router and has no monitor attached to it (console) so on reboot I'm not able to follow startup of the services when entering runlevel 2. Is there an easy way to redirect these messages into a file? Thanx, Peter

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Re: [suse-security] Re: Secure By Default - PLEASE!
by dproc＠dol.net 30 Aug '00

30 Aug '00

On Tue, 22 Aug 2000, juergen.braukmann(a)ruhr-west.de wrote: > > that includes telnet etc) and safe: just the safe services (ssh et > > all). That would mean including 3 versions of inetd.conf and rc.config, > > each with a short description of the differences/potential problems. That > > good in theory but... Say, you select "secure inetd" and you select > "Apache". secure inetd will close port 80. Apache needs port 80. Hmmm. > Either Apache would auto select "less secure inetd.conf" or apache / > httpd / THE HELP SYSTEM would not work. Lot's of fun for the newbe that > sais "I want it secure, but why does help not work" (Sorry for the late entry to this thread - I am catching up on a full mailbox) I think your example is wrong at least for 6.3 I activated the help system using rc.config. httpd ports are disabled in inetd.conf. But 6.3 and 5.3 YaST1 can run httpd as a daemon in runlevel 2 - so port 80 remains open all the time. Running httpd this normal way means it is not protected by inetd.conf or hosts.deny. Try it out. I think there is more than one rc.config option so you are correct, it would be easy to confuse a newbie and make help fail. BTW - I know I can protect my help system daemon with a firewall packet filter and with inetd/tcpd. I only want it to work for localhost - everyone else should see dropped connections ideally. But is there an application level way to protect it also - in case my firewall fails? dproc

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Re: [suse-security] bootscreen
by Kalle Kivimaa 30 Aug '00

30 Aug '00

Markus Gaugusch <markus(a)gaugusch.dhs.org> contributed: > i'd also like to redirect output of initscripts to a file for all my > servers i can't reach because they are far away :) The solution below is untested as I personally don't require the functionality and have no machine to test it on right now :/ /etc/rc.d/rc: Add the following line right above "exec 0<> $CONSOLE 1>&0 2>&0": export CONSOLE=/var/log/lastinit

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Re: [suse-security] port 8
by semat＠wawa.eahd.or.ug 30 Aug '00

30 Aug '00

> Aug 27 20:06:14 noname kernel: Packet log: input ACCEPT eth0 PROTO=1 > 24.8.72.245:8 xxx.yyy.zzz.www:0 L=36 S=0x00 I=56281 F=0x0000 T=118 > (#6) > > > Is this a hole in the firewall setup? I do not have the experience to > know. > > Thank you > Russell Most likely this was just a normal ping. Alook at /etc/protocols will show you that proto=1 is icmp.

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Re: [suse-security] port 8
by Bastian Friedrich 30 Aug '00

30 Aug '00

Hi! Russell Evans behauptete am 30 Aug 2000 um 18:51: > FW_ALLOW_PING_FW="yes" > FW_ALLOW_PING_DMZ="no" > > The following was logged. My hostname and IP changed. > > Aug 27 20:06:14 noname kernel: Packet log: input ACCEPT eth0 PROTO=1 24.8.72.245:8 xxx.yyy.zzz.www:0 L=36 S=0x00 I=56281 F=0x0000 T=118 (#6) You probably missed the "PROTO=1" bit of that line. Have a look at /etc/protocols: icmp 1 ICMP # internet control message protocol So you are not experiencing tcp connection attempts on port 8, but ICMP requests. Looking further: $ grep 8 /usr/i486-glibc20-linux/include/netinet/ip_icmp.h [...] #define ICMP_ECHO 8 /* Echo Request */ [...] So what you are experiencing are simple pings... Bye, Bastian -- Bastian Friedrich bastian(a)bastian-friedrich.de Adress & Fon available on my HP http://www.bastian-friedrich.de/ \~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\ \ Don't hate yourself in the morning - sleep till noon.

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Re: [suse-security] port 8
by Gerry Doris 30 Aug '00

30 Aug '00

Someone from cx280252-a.phnx1.az.home.com (a cable modem user in Phoneix, AZ on the @home network) pinged your host. This is an icmp request (PROTO=1) type 8. It is not an connection attempt on port 8. Nothing to worry about. Gerry On 30 Aug 2000, Russell Evans wrote: > I am running the firewall update for SuSE 6.4 with the following > settings. > > FW_DEV_WORLD="eth0" > FW_DEV_INT="" > FW_DEV_DMZ="" > FW_ROUTE="no" > FW_MASQUERADE="no" > FW_MASQ_NETS="" > FW_MASQ_DEV="$FW_DEV_WORLD" > FW_PROTECT_FROM_INTERNAL="yes" > FW_AUTOPROTECT_GLOBAL_SERVICES="yes" > FW_SERVICES_EXTERNAL_TCP="22 53 110 25" > FW_SERVICES_EXTERNAL_UDP="514 53" > FW_SERVICES_DMZ_TCP="" > FW_SERVICES_DMZ_UDP="" > FW_SERVICES_INTERNAL_TCP="" > FW_SERVICES_INTERNAL_UDP="" > FW_TRUSTED_NETS="" > FW_SERVICES_TRUSTED_TCP="" > FW_SERVICES_TRUSTED_UDP="" > FW_ALLOW_INCOMING_HIGHPORTS_TCP="dns" > FW_ALLOW_INCOMING_HIGHPORTS_UDP="yes" > FW_SERVICE_DNS="yes" > FW_SERVICE_DHCLIENT="no" > FW_SERVICE_DHCPD="no" > FW_FORWARD_TCP="" > FW_FORWARD_UDP="" > FW_REDIRECT_TCP="" > FW_REDIRECT_UDP="" > FW_LOG_DENY_CRIT="yes" > FW_LOG_DENY_ALL="yes" > FW_LOG_ACCEPT_CRIT="yes" > FW_LOG_ACCEPT_ALL="no" > FW_KERNEL_SECURITY="yes" > FW_STOP_KEEP_ROUTING_STATE="no" > FW_ALLOW_PING_FW="yes" > FW_ALLOW_PING_DMZ="no" > FW_ALLOW_FW_TRACEROUTE="no" > FW_ALLOW_FW_SOURCEQUENCH="yes" > FW_MASQ_MODULES="autofw cuseeme ftp irc mfw portfw quake raudio user > vdolive" > > The following was logged. My hostname and IP changed. > > > Aug 27 20:06:14 noname kernel: Packet log: input ACCEPT eth0 PROTO=1 > 24.8.72.245:8 xxx.yyy.zzz.www:0 L=36 S=0x00 I=56281 F=0x0000 T=118 > (#6) > > > Is this a hole in the firewall setup? I do not have the experience to > know. > > Thank you > Russell > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: suse-security-unsubscribe(a)suse.com > For additional commands, e-mail: suse-security-help(a)suse.com > Gerry "The lyf so short, the craft so long to learne" Chaucer

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user masquerade in postfix
by Arndt Groll 30 Aug '00

30 Aug '00

hello, does anybody know what i must do or insert in main.cf to masquerade a user in the address of user(a)firma.de? i have read many about domain masquarde, but i'm not able to find something about user masquarde - by the way - i know how this can be made in qmail but i want do that in postfix. is it support by postfix or must i play with perl? A. Groll

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Relaying with Authentification, Secure Password transmission
by Boris Kantwerk 29 Aug '00

29 Aug '00

Hi *! How do I tell sendmail, to relay mails for all users sending a correct login and password independent from the host from which they send the mail? Additional I want to enable secure password transmission for sendmail, popper and ftpd and don't know how! Thanx, Boris.

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Dialin/VPN/Firewall
by Erwin Zierler - Stubainet 29 Aug '00

29 Aug '00

Hi, I recently have installed a firewall machine (SuSE 6.4, kernel 2.2.14) for a company connected to the internet via a 64K permanent leased line. Initially I was told there were no requirements to offer any services from inside the company to the outside (www, mail, etc.) so I went with a fairly simple setup (no DMZ) which would also fit their budget. Setup: Internet - Cisco Router - Linux Firewall - LAN While setting up the machine on site the IT department found out, that their new provider had taken over the domain name (as requested) and provided IP addresses for firewall.company.com, mail.company.com and also www.company.com all routed to the same network. Soon I was confronted with the wish to make their NT based mail server - residing on the internal LAN and formerly sending and recieving mail via a dialup-link (to the old provider) - talking to the outside world. Setting up a second firewall and a DMZ (which for me would have been the best solution security wise) was not an option. So I went with the ipmasqadm tool and now I am portforwarding mail to and from mail.company.com over the firewall machine. I am not very happy with this as it just opens more potential vulnerabilities. First question: does anyone have a better solution for this (given the setup and restrictions I described above)? Now, after connecting those guys to the internet they contacted me again with the next wish: certain employees are supposed to be able to connect from home/hotel/anyplace (of course outside the LAN) via firewall (or what they suggested first - a dialin server INSIDE the LAN *sigh*) to certain services inside their LAN (mainly fileservices). Doh! Second question: What would be a good/the best solution to give them access? I am extremly reluctant to let netbios and similar protocols cross the firewall, I also dont really want to provide dialup access on the firewall box and even less on a machine inside the LAN. Anything that will be transferred would have to be encrypted since I can't imagine they would want to transmit confidential material without some sort of protection. Ok, I started reading up on VPNs and related material. To be short, I am not familiar with this topic yet so I thought I try and get some advice from this mailinglist first before I waste hours of investigating useless material. All hints and/or links to material discussing this topic are very much appreciated. Thanks, Erwin Erwin Zierler | Web-/Hostmaster - Stubainet | Email: Erwin.Zierler(a)stubainet.at / webmaster(a)stubainet.at | Mobil: 0664 - 130 67 91 Tel.: 05225 - 64325 Fax 99

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Secure By Default - PLEASE!
by Nix 28 Aug '00

28 Aug '00

How bout it SuSE? I have bought every version of SuSE since 5.0, I have Installed >30 SuSE servers for various clients and given away 200 copies of the SuSE 6.4 demo CD at a Govt Expo (in Australia) (Thanks to Michaela Geuthner [mailto:mg@suse.de] for the promo material he shiped me at short notice from Germany) I love SuSE, and thinks it's the best Distro available, yet, a disabled by default policy would IMHO be the best thing SuSE could ever do. As far as I'm concerned the only thing that should be enabled by default is sshd and _thats's_ even debatable. Face it, it's not going to make it any harder for your average desktop flunkie who want's to setup a kde box and browse the web. If they want to run a personal web server or ftp server then that _should_ know how to enable it from inetd.conf etc, or they should NOT be running the thing. I think the harden SuSE script, and SuSE firewall is brilliant, but half of the things harden_suse does should be _default_ not options available in an optional package in the sec series.... PLEASE PLEASE make a few simple changes to the defaults to help make SuSE the most secure Mainstream linux distro out there in. Peter Nixon Senior Security Consultant IT Audit & Consulting (ITAC) Pty Ltd http://www.itaudit.com.au mailto:petern@itaudit.com.au --snip-- >To: BUGTRAQ(a)SECURITYFOCUS.COM > >Aleph One wrote: > > CERT Advisory CA-2000-17 Input Validation Problem in rpc.statd > > > > Original release date: August 18, 2000 > > Source: CERT/CC > > > > A complete revision history is at the end of this file. >.. > > RedHat > > > > http://www.redhat.com/support/errata/RHSA-2000-043-03.html > > > >It should be noted that Red Hat states: >"Although there is no known exploit for the flaw in rpc.statd, Red Hat urges >all users running rpc.statd to upgrade to the new nfs-utils package." > >This is wrong. > >Because of a message posted by "ron1n - <shellcode(a)HOTMAIL.COM>" on the 5th >of August to Bugtraq. > >I quote: >"Included below is an exploit for the recently exposed linux rpc.statd >format string vulnerability[0]. I have tailored it towards current Redhat >Linux 6.x installations. It can easily be incorporated into attacks against >the other vulnerable Linux distributions." > >I hope Red Hat updates this information. Although I really hope they'll >just disable rpc.* services, most things in inetd, and other daemons *BY >DEFAULT*. If a user can't figure out how to turn on a service, they >probably shouldn't be running the service in the first place. This alone >would stop most of the "remote root in default" problems that Red Hat (and >other Linuxes) seem to face. OpenBSD gets this correct, how hard can it be >for the various Linux distrubtions to insert some #s in inetd.conf, or have >things chmod -x by default? > >-- > www.kuro5hin.org -- technology and culture, from the trenches.

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ssh
by semat＠wawa.eahd.or.ug 28 Aug '00

28 Aug '00

Hello, I have been running ssh for some time time now however I have been using password authentication. I would now like to use RSA too. I need help on how this is done. As well I would like to have my set up such thatboth RSA and password authentication have to work before someone can login. This is simply because I provide ftp and if such a password is sniffed then it can be used to start an ssh session. However if I use RSA authentication as well then there would be another line of defence against sniffed passwords.

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AW: AW: [suse-security] Popper verbosity
by Klug, Boris 28 Aug '00

28 Aug '00

Hi! so how can I disable the popper logging of tcpd? Havent found something in "man tcpd". Maybe running popper in deamon mode is a good idea? -- i.A. Dipl.-Inf. Boris Klug, boris.klug(a)ibs-ag.de, http://www.ibs-ag.de/ IBS AG engineering consulting software, The Quality Company Rathausstraße 56, 56203 Höhr-Grenzhausen, Fon: 02624/9180-0, Fax: -200 > -----Ursprüngliche Nachricht----- > Von: Roman Drahtmueller [mailto:draht@suse.de] > Gesendet: Sonntag, 27. August 2000 08:50 > An: Jürgen Bloß > Cc: suse-security(a)suse.com > Betreff: Re: AW: [suse-security] Popper verbosity > > > > Hello again! > > > > Indeed, the suggested solution does not work! > > But there has to be a better way than rebuild the popper! > > Problem is: I couldn't find the output line in the popper > source. Could > > it be that inetd is doing this log, before calling popper??? > > But I surely son't want to rebuild the inetd! > > > > Doesn't anybody else experience this problem that popper is > cluttering > > the /var/log/messages file? > > > > There *must* be a way to stop this logging-call. Perhaps by > configuring > > syslogd??? > > > > Jürgen > > To clear this up: > > There are possibly two lines per connection in your syslogs: > > Aug 27 08:36:32 para popper[10193]: connect from 127.0.0.1 (127.0.0.1) > Aug 27 08:37:01 para popper[10193]: Stats: shotdead 1 415 0 0 > > > The first line is from /usr/sbin/tcpd (the tcp wrapper) in > /etc/inetd.conf. It's not the popper program's fault - in > fact, it doesn't > even know that tcpd wrote a log since it was started from him. > > The second line vanishes if you remove the "-s" from the > popper line in > /etc/inetd.conf. This works, you find the relevant code in > pop_updt.c:86 > and pop_log.c. > > Thanks, > Roman. > -- > - > - > | 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) | > - > - > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: suse-security-unsubscribe(a)suse.com > For additional commands, e-mail: suse-security-help(a)suse.com >

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mail as root
by Roman Drahtmueller 27 Aug '00

27 Aug '00

Hi, After I made a brief comment on a mailinglist that said "don't mail as root". I got half a dozen replies asking for the reason, and I said I'll write it down for all: Unix/Linux are multi-user operating systems. The goal is to be able to seperate users from each other. There are only few categories of users, and seen from the kernel's perspective, there are only two: user and superuser. The superuser on the system (root) has no restriction wrt what he can do in the system, whereas other users must confirm to the (permission-) rules that the super user configured (when in doubt, that was the distributor) >From this perspective, it should be easy to see that using the least privilege possible and needed for a task is most secure. Especially in cases where a program uses data that comes from an untrusted source this is strongly advised. How do you know that a .jpg file that you received from your friend does indeed confirm to the JPEG image compression standards (netscape prior to version 4.74 had a bug in the jpeg handling code that could, if exploited by a specially crafted jpeg image, enable an attacker to execute arbitrary machine code on the machine the netscape browser runs on.) The majority of programs do have this property (since you wish to have them something done, of course). The most suitable for the purpose of this mail are * mail user agents (MUAs) * chat clients (such as IRC) * browsers (such as netscape) * multi media players (such as mp3 players and image viewers) If your mail program is written in poor style, it might contain a bug that allows an attacker to do nasty things with your machine. pine used to have such a bug a while ago, for example. If this happens as user root, the possible damage to your machine is not restricted in any way, if it happens as user foo, the attacker may still have to obtain root rights to gain complete access to the system. Thanks, Roman. -- - - | 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) | - -

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