March 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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multi-services server securing
by Gediminas Grigas 16 Aug '00

16 Aug '00

Hello there, I feel erroneusly (?) secure after .host.denyed in.telnetd and in.sshd from everywhere except one pc, which is denying all exept keyboard. I belive that if i can keep hosts.deny and hosts.allow files safe, and from time to time patch most actual security holes i`ll be conditionaly safe. Em i wrong? Probably I do. I just cant imaginate how system can be cracked in lower stage, so that is my problem. I heard that inetd is very insecure, and some peoples using tcpd (or soundlike). I run harden_suse, but was forced to answer 8/10 to no, as my server should provide a lot of public services, and have world writible directories as well. And thats right - this script was developed not for systems like mine one. However i`ll run SuSE-firewall-3.0 script, to make my system even stronger. But thats all. I dont know what can i do else. I should keep folowing services open: httpd; smptd; pop3d; ftpd; snmpd; named; inetd; sshd; nscd. So if you know how to keep them at minimal risk, or know some holes at those, i would be very gratefull for any info and/or tips. I dont ask to do work for me - link to good manual would be nice too. By the way i have SuSE 6.3 (2.2.13). Thanks in advice. Sincerely Yours, Gediminas Grigas mailto:gedas@kryptis.lt

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possible security problem with weak perms on /dev/fd[01] in suse 6.3 distro
by techno＠crosslink.net 20 Apr '00

20 Apr '00

Hi. I thought I would notify you of my findings on a possible security problem within suse 6.3. Below is an excerpt about /dev/fd[01] permissions that I wrote a few days ago. I'm not sure if this has been noticed before. If not, I hope the information does you some good. I'd appreciate any responses on the matter that you can give, thanks :). [cut] Out of the box, SuSE 6.3 allows global rw access on the primary and secondary floppy drive (/dev/fd0 and /dev/fd1). Because devices can be written to directly, just like anything else, the floppy drives do not need to be mounted for any user to write data to a disk that has been left in the drive. Depending on the systems setup, this can be a very malicious tool. If the system boots SuSE directly from a floppy disk, chances are the disk is left in the drive while the system is up. If a user were to log on, and decide to use 'dd' (amongst a variety of other tools, or even just a 'cat FILE > /dev/fd0') the boot floppy would be ruined. A lazy sysadmin who didn't check the logs would not see that the bootdisk had been ruined, and upon reboot, may find himself with a dead box until the disk can be replaced. This is just one scenario where the weak perms on the devices can be dangerous. I just recently noticed this after installing SuSE 6.3 on one of my systems over a month ago. The permissions on /dev/fd[01] have been checked on several SuSE 6.3 systems and all check out as o+rw. If you are running SuSE 6.3 and have users other than yourself logging in, your best bet is to 'chmod o-rw /dev/fd0'. I cannot think of one good reason why SuSE would have set permissions on /dev/fd[01] so weak. If you can give any suggestions or feedback, an e-mail would be appreciated. -- Bryan Hughes init(a)crashdot.org

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syslog doesn't log after rotation
by Michael Balzer 18 Apr '00

18 Apr '00

dear suse security team, on my standard suse 6.3 internet server, i have to do "/sbin/init.d/syslog reload" after any log rotation. if i don't restart it, syslog will not write to the new log files. this is a security issue, as i cannot track security problems without log entries. i already sent this as a bug report to suse a long time ago but never got any response. what can i do? regards, michael balzer -- b&b computersysteme * kämperheide 10 * 58285 gevelsberg * germany fon +49 2333 913924 * fax +49 2333 913925 * http://www.bbcomp.de

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passwords limited 8 characters
by Ertan Sekmen 18 Apr '00

18 Apr '00

hello, is there any probram come with suse 6.3 to allow users have password more than 8 characters, or do i need to compile ? Is this called md5, ?

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mouse permissions
by Peter Münster 18 Apr '00

18 Apr '00

Hello, on SuSE 5.3 /dev/psaux (PS2-mouse) was read and write for all users, now (with SuSE >= 6.2) it's read only (perms = 664). Is there any risk, to enable write permissions again on this device? (quake needs it! ;) Cheers, Peter -- Peter Münster **** Brittany **** France URL: http://gmv.spm.univ-rennes1.fr/~peter/

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How to decrypt shell code of an exploit?
by Frank Derichsweiler 18 Apr '00

18 Apr '00

Hi list, the box of a friend was hacked: /bin/ps /bin/login /bin/ls were replaced / trojaned. The original files were placed in /bin/bincp (which is not shown by ls, but cd into that dir works fine) Luckyly I found some source within a log of another machine. Comments show that there is an unsigned char shellcode[] = with some rows of "\x ...\x" numbers. I assume that there is the coding of a shell command. Unfortunately I do not know how to "read" the command. Translating the hex numbers into decimal and using an ASCII table does not give a usefull result. Any idea? Tips who to detect which root kit was used are welcome, too. TIA Frank

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login & password aging
by Schoeberle Daniel 04 Apr '00

04 Apr '00

Hi! I have a problem concerning password aging on SuSE 6.3. If a password expires the user is prompted for the new password at the login time. The problem is that he/she can enter an empty one just by hitting Enter twice. No checks for minimum password lenght, no cracklib checks - and these are enabled in etc/login.defs. Changing the password from the prompt works normally with all the checks in effect. So, is there a way to enable atleast the minimum password lenght check? Any comments and/or suggestions would be appreciated. Regards, Daniel.

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Real bad log entry
by Chrissy 01 Apr '00

01 Apr '00

This looks terrible.. anyone have any ideas? Mar 30 20:45:00 rox /USR/SBIN/CRON[16114]: (root) CMD ( test -x /usr/lib/cron/run-crons && /usr/lib/cron/run-crons ) Mar 30 20:46:14 rox ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P ~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P~P Mar 30 20:46:55 rox named[380]: Cleaned cache of 57 RRsets I've got sendmail, web, named, and identd open to the world.. and pop3, ftp, ssh open to accepted ip ranges (via IPCHAINS) Please help..this sucks. Chrissy

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SuSE Security Announcement - ircii
by marc＠suse.de 30 Mar '00

30 Mar '00

-----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SuSE Security Announcement Package: ircii < 4.4M Date: Thu, 23 Mar 2000 11:04:19 GMT Affected SuSE versions: all Vulnerability Type: remote user compromise SuSE default package: no Other affected systems: all unix systems using ircii < 4.4M ______________________________________________________________________________ A security hole was discovered in the package mentioned above. Please update as soon as possible or disable the service if you are using this software on your SuSE Linux installation(s). Other Linux distributions or operating systems might be affected as well, please contact your vendor for information about this issue. Please note that we provide this information on an "as-is" basis only. There is no warranty whatsoever and no liability for any direct, indirect or incidental damage arising from this information or the installation of the update package. _____________________________________________________________________________ 1. Problem Description The package ircii is an irc client which is used to connect to irc servers and chat with other users. A buffer overflow in the dcc chat feature was found which is exploitable by remote users. 2. Impact Remote users may execute commands as the user running ircii. 3. Solution Update the package from our FTP server. ______________________________________________________________________________ Please verify these md5 checksums of the updates before installing: (For SuSE 6.0, please use the 6.1 updates) 0d928f56148aaa86c0015bbce49d3561 ftp://ftp.suse.com/pub/suse/axp/update/6.1/n1/ircii-4.4M-0.alpha.rpm e06dfc1254128cb1683e0487f168bf76 ftp://ftp.suse.com/pub/suse/axp/update/6.1/n1/irciihlp-4.4M-0.alpha.rpm 56e00c8e2260b2949ce0536035af479f ftp://ftp.suse.com/pub/suse/i386/update/6.1/n1/ircii-4.4M-0.i386.rpm 29d123a6ac148827c3b2de2a552f4fa8 ftp://ftp.suse.com/pub/suse/i386/update/6.1/n1/irciihlp-4.4M-0.i386.rpm 10411aceecd18fc7ff7e6e5445e705ec ftp://ftp.suse.com/pub/suse/i386/update/6.2/n1/ircii-4.4M-0.i386.rpm e8d430af732bd22f8e460f1ff9f45a77 ftp://ftp.suse.com/pub/suse/i386/update/6.2/n1/irciihlp-4.4M-0.i386.rpm 773184cd39e5bffd72f8432a5efdd24f ftp://ftp.suse.com/pub/suse/i386/update/6.3/n1/ircii-4.4M-0.i386.rpm 32738de26730d7442fa1adf992bf37fc ftp://ftp.suse.com/pub/suse/i386/update/6.3/n1/ircii-4.4M-1.i386.rpm 49373ad8be6b9ef1c1c4a1c21481a639 ftp://ftp.suse.com/pub/suse/axp/update/6.3/n1/irciihlp-4.4M-1.alpha.rpm 80505bfa6f08330f5a129d59ae58b51a ftp://ftp.suse.com/pub/suse/ppc/update/6.3/n1/ircii-4.4M-0.ppc.rpm 4a72afe3f807cf1da2c8859c2a3fb743 ftp://ftp.suse.com/pub/suse/ppc/update/6.3/n1/irciihlp-4.4M-0.ppc.rpm 6c2c3e7773760a9da2d2fa67b07f564a ftp://ftp.suse.com/pub/suse/i386/update/6.4/n1/irciihlp-4.4M-1.i386.rpm ______________________________________________________________________________ You can find updates on our ftp-Server: ftp://ftp.suse.com/pub/suse/i386/update for Intel processors ftp://ftp.suse.com/pub/suse/axp/update for Alpha processors or try the following web pages for a list of mirrors: http://www.suse.de/ftp.html http://www.suse.com/ftp_new.html Our webpage for patches: http://www.suse.de/patches/index.html Our webpage for security announcements: http://www.suse.de/security If you want to report vulnerabilities, please contact security(a)suse.de ______________________________________________________________________________ SuSE has got two free security mailing list services to which any interested party may subscribe: suse-security(a)suse.com - moderated and for general/linux/SuSE security discussions. All SuSE security announcements are sent to this list. suse-security-announce(a)suse.com - SuSE's announce-only mailing list. Only SuSE's security annoucements are sent to this list. To subscribe to the list, send a message to: <suse-security-subscribe(a)suse.com> To remove your address from the list, send a message to: <suse-security-unsubscribe(a)suse.com> Send mail to the following for info and FAQ for this list: <suse-security-info(a)suse.com> <suse-security-faq(a)suse.com> _____________________________________________________________________________ This information is provided freely to everyone interested and may be redistributed provided that it is not altered in any way. 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