October 1999 - openSUSE Security - openSUSE Mailing Lists

Re: [suse-security] Firewall/asymmetric subnet
by tdie＠gmx.net 25 Oct '99

25 Oct '99

Hi Christoph, I'm afraid you cannot build asymetric subnets. This is because subnets are generated by applying a bitmask to the former host part, which is just a mathematic operation like subnets=(2^former-host-bits/2^netmask-bits)-2. This means all subnets are of the same size. Consider a bigger netmask, why not divide the adress space by 8, which means you could use 14 adresses per subnet. Hope that helps ... Thorsten ! -- Sent through Global Message Exchange - http://www.gmx.net

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[suse-security] Firewall/asymmetric subnet
by christoph.schaefer＠student.uni-tuebingen.de 25 Oct '99

25 Oct '99

Salut, I have a question about subnetting. I want to build following network: Internet | | Router | eth0| eth1 Firewall--------Intranet eth2| | | DMZ Where the intranet will be masqueraded by the firewall, but the DMZ (with services like www, smtp, etc..) has global ip's. So eth0 needs a global ip for correct masquerading, router needs a global ip, eth2 needs a global ip for DMZ. If I do not build two subnet (router, eth0 of firewall and dmz, eth2 of firewall) the routing of the firewall will not work, because dmz and router are in the same subnet. That is why I made two subnet. I can use 128 global ips, but with my solution 62 ips (64 minus router minus eth0 of firewall) are lost, because I have not managed to build asymmetric subnet. Is there any other possibility? Like asymmetric subnetting? I have read lots of HOWTOS, but none matched my problem, they were all building symmetric subnets. Thanks a lot for every helping hand! Best regards, Christoph --- The primary purpose of the DATA statement is to give names to constants; instead of referring to pi as 3.141592653589793 at every appearance, the variable PI can be given that value with a DATA statement and used instead of the longer form of the constant. This also simplifies modifying the program, should the value of pi change. -- FORTRAN manual for Xerox Computers

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SuSE Security Announcement - ypserv
by Marc Heuse 24 Oct '99

24 Oct '99

-----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SuSE Security Announcement Package: ypserv prior 1.3.9 Date: Tue Sep 28 08:38:50 CEST 1999 Affected: all linux distributions using the ypserv package ______________________________________________________________________________ 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 that we provide this information on "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 ypserv is the former "yellow pages", now called NIS information service, which is used for e.g. central network user account management. Several vulnerability exists: ypserv prior 1.3.9 allows an administrator in the NIS domain to inject password tables; rpc.yppasswd prior 1.3.6.92 has got a buffer overflow in the md5 hash generation [SuSE linux is unaffected by this, other linux falvors are]; rpc.yppasswdd prior 1.3.9 allows users to change GECO and login shell values of other users. 2. Impact If administrator access to one server in the NIS domain is compromised, access to the whole domain can be achieved. On some linux distributions other than SuSE, The rpc.yppasswdd service may halt unexpectedly. It is theoretically possible to execute arbitary code on these systems too. User information can be changed and restricted accounts opened. 3. Solution Updated the package from our FTP server. ______________________________________________________________________________ Here are the md5 checksums of the upgrade packages, please verify these before installing the new packages: abe34d8d1831550059b3fad160fe41f5 ypserv-1.3.9-0.i386.rpm (6.1) 6937d10896d2b5beb18471491ca57781 ypserv-1.3.9-0.alpha.rpm (AXP) 19472f128099cb1e311f2db247acd39f ypserv-1.3.9-0.i386.rpm (6.2) For SuSE 6.0 users: please use the 6.1 version. ______________________________________________________________________________ You will find the update on our ftp-Server: ftp://ftp.suse.com/pub/suse/i386/update/6.1/n1/ypserv-1.3.9-0.i386.rpm ftp://ftp.suse.com/pub/suse/axp/update/6.1/n1/ypserv-1.3.9-0.alpha.rpm ftp://ftp.suse.com/pub/suse/i386/update/6.2/n1/ypserv-1.3.9-0.i386.rpm Webpage for patches: http://www.suse.de/patches/index.html or try the following web pages for a list of mirrors: http://www.suse.de/ftp.html http://www.suse.com/ftp_new.html ______________________________________________________________________________ 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 send 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> _____________________________________________________________________________ If you want to report *NEW* security bugs in the SuSE Linux Distribution please send an email to security(a)suse.de or call our support line. You may use pgp with the public key below to ensure confidentiality. ______________________________________________________________________________ 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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problem with nfs
by sebastian.kleine＠gmx.net 24 Oct '99

24 Oct '99

Hy I think this is not the right mailinglist to post this question but I don't know where to post it and I don't want to subscribe to every list. That would be quit a lot of mails every day. My problem: I had Suse 6.1 on my local net using nfs to export serveral directories (/home and others). It worked. Than I upgraded to Suse 6.2. At first I got a lot of messages with problems setting suid/uig = -2 (or something like that). There is a patch for this and I installed it. Now this problem is solved, but I've got another problem: On a normal machine (which mounts the directories via NFS) I can't write to the directories. It always says: permission denied. This is a very serious problem for me, because nearly everything doesn't work anylonger. I very much appreciate every help! Thanks. Sebastian

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problem with nfs
by sebastian.kleine＠gmx.net 24 Oct '99

24 Oct '99

Hy I think this is not the right mailinglist to post this question but I don't know where to post it and I don't want to subscribe to every list. That would be quit a lot of mails every day. My problem: I had Suse 6.1 on my local net using nfs to export serveral directories (/home and others). It worked. Than I upgraded to Suse 6.2. At first I got a lot of messages with problems setting suid/uig = -2 (or something like that). There is a patch for this and I installed it. Now this problem is solved, but I've got another problem: On a normal machine (which mounts the directories via NFS) I can't write to the directories. It always says: permission denied. This is a very serious problem for me, because nearly everything doesn't work anylonger. I very much appreciate every help! Thanks. Sebastian

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problem with nfs
by sebastian.kleine＠gmx.net 24 Oct '99

24 Oct '99

Hy I think this is not the right mailinglist to post this question but I don't know where to post it and I don't want to subscribe to every list. That would be quit a lot of mails every day. My problem: I had Suse 6.1 on my local net using nfs to export serveral directories (/home and others). It worked. Than I upgraded to Suse 6.2. At first I got a lot of messages with problems setting suid/uig = -2 (or something like that). There is a patch for this and I installed it. Now this problem is solved, but I've got another problem: On a normal machine (which mounts the directories via NFS) I can't write to the directories. It always says: permission denied. This is a very serious problem for me, because nearly everything doesn't work anylonger. I very much appreciate every help! Thanks. Sebastian

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problem with nfs
by sebastian.kleine＠gmx.net 24 Oct '99

24 Oct '99

Hy I think this is not the right mailinglist to post this question but I don't know where to post it and I don't want to subscribe to every list. That would be quit a lot of mails every day. My problem: I had Suse 6.1 on my local net using nfs to export serveral directories (/home and others). It worked. Than I upgraded to Suse 6.2. At first I got a lot of messages with problems setting suid/uig = -2 (or something like that). There is a patch for this and I installed it. Now this problem is solved, but I've got another problem: On a normal machine (which mounts the directories via NFS) I can't write to the directories. It always says: permission denied. This is a very serious problem for me, because nearly everything doesn't work anylonger. I very much appreciate every help! Thanks. Sebastian

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Secure ODBC
by Jochen Mader 23 Oct '99

23 Oct '99

I'd like to allow people to manage their sites via internet over an ODBC-connection but I don't know how secure it is to do so. Are the passwords being submitted in clear text or are they being encrypted? Is it possible to secure ODBC-connections in some way? See ya Jochen

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Re: [suse-security] Firewall with SuSE 6.2]
by Jochen Mader 23 Oct '99

23 Oct '99

Thanx to all, I decided to do subnetting on my network because it's the most secure way to protect my network (alas that this means that I have to to some serious changes to the structure of our network). By the way: The arp-tip really works, but as mentioned: another service another possible security hole.

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Firewall/router - doesn't forward
by romba＠fem.maschinenbau.uni-dortmund.de 23 Oct '99

23 Oct '99

Hello! We are currently trying to build a packet filtering firewall using SUSE Linux 6.2 and ipchains. The hardware used is a Pentium 133 with two Level One NICs using the Realtek 8139 chipset. >From what we read in the literature (Firewall and Ipchains HowTo, several articles in the german magazine ct etc.) it seemed quite manageable, but then reality struck. After several successless tests with a bigger installation we set up an installation almost identical to the one shown in part 6.3 of the "Firewall and Proxy Server HOWTO" written by Mark Grennan, the only difference being the IP-adresses for the outside part. Our setup passes all the tests described except one - it doesn't forward. I can ping any computer from the firewall/router, I can ping both sides of the firewall from the LAN, but I can only ping the outside adress from the outside and I can't get through it. IP-forwarding is switched on and all default policies in ipchains are set to ACCEPT. We are quite desperate (and my boss is losing patience), so any ideas are highly welcome. Might it be useful to try some other network adapters? Is there something we have overlooked? Is there a fault in the HOWTO? Best regards

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