Re: rsync security advisory
On Thu 04 Dec 2003, Martin Pool wrote: - rsync version 2.5.6 contains a heap overflow vulnerability that can be used to remotely run arbitrary code. Is this specific to 2.5.6, or are earlier versions also vulnerable? Important detail, as it makes the difference between needing to upgrade older rsync's as well, or only those that are 2.5.6... As Debian provides security patches for the stable release (which contains rsync 2.5.5), I'm wondering whether an update for that is necessary. Paul Slootman -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
Re: [rsync-announce] rsync security advisory
[EMAIL PROTECTED] wrote: rsync 2.5.6 security advisory - December 4th 2003 Background -- The rsync team has received evidence that a vulnerability in rsync was recently used in combination with a Linux kernel vulnerability to compromise the security of a public rsync server. While the forensic evidence we have is incomplete, we have pieced together the most likely way that this attack was conducted and we are releasing this advisory as a result of our investigations to date. Would this be the rsync.gentoo.org box that was compromised on 12-02? Daemian Mack -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
Re: rsync security advisory
On Thu 04 Dec 2003, Paul Haas wrote: On Thu 04 Dec 2003, Martin Pool wrote: - rsync version 2.5.6 contains a heap overflow vulnerability that can be used to remotely run arbitrary code. Is this specific to 2.5.6, or are earlier versions also vulnerable? Important detail, as it makes the difference between needing to upgrade older rsync's as well, or only those that are 2.5.6... As Debian provides security patches for the stable release (which contains rsync 2.5.5), I'm wondering whether an update for that is necessary. Sure looks necessary to me. Thanks. The Debian security team are working on a fixed 2.5.5 for stable now. In fact, it's done, but needs to be built on all the architectures that Debian supports before an announcement can go out. I've also built 2.5.7 for unstable/testing, but as at this time nothing is being installed into the archives (due to the earlier compromise), it won't be available for at least a couple of days :-( In the meantime, interested parties may download http://www.wurtel.cistron.nl/rsync_2.5.7-1_i386.deb (md5sum 985e720f7502c2df9685a2202d36692d) and install that with dpkg -i taking into account its dependencies: libc6 (= 2.3.2.ds1-4), libpopt0 (= 1.7) Paul Slootman signature.asc Description: Digital signature -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
Re: rsync security advisory
On Thu, 4 Dec 2003, Paul Slootman wrote: Date: Thu, 4 Dec 2003 11:34:44 +0100 From: Paul Slootman [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Re: rsync security advisory On Thu 04 Dec 2003, Martin Pool wrote: - rsync version 2.5.6 contains a heap overflow vulnerability that can be used to remotely run arbitrary code. Is this specific to 2.5.6, or are earlier versions also vulnerable? Important detail, as it makes the difference between needing to upgrade older rsync's as well, or only those that are 2.5.6... As Debian provides security patches for the stable release (which contains rsync 2.5.5), I'm wondering whether an update for that is necessary. Sure looks necessary to me. I downloaded the Debian Stable rsync from http://ftp.us.debian.org/debian/pool/main/r/rsync/rsync_2.5.5.orig.tar.gz with the debian patch http://ftp.us.debian.org/debian/pool/main/r/rsync/rsync_2.5.5-0.1.diff.gz to get what I hope is the source for 2.5.5-0.1. I then got the patch http://rsync.samba.org/ftp/rsync/rsync-2.5.6-2.5.7.diff.gz It mostly applied to 2.5.5-0.1. It succeeds on all of the .c files except for cleanup.c. It fails on all the non-.c files, mostly because those changes update the string 2.5.6 to 2.5.7, which fails. If I understand the attack, it looks like the parts of the rsync-2.5.6-2.5.7.diff which apply to the Debian Stable rsync-2.5.5-0.1 are sufficient to block such attacks. The change to cleanup.c fails because the function being changed doesn't exist in 2.5.5. That change is -void close_all() +void close_all(void) I don't understand what that changes in the context of a buffer overflow attack. On the assumption it does make a difference, you could change log.c like so -void log_open() +void log_open(void) and -void log_close() +void log_close(void) which fixes the two places in 2.5.5-0.1 where there are empty parameter lists in a function prototype. -- Paul Haas [EMAIL PROTECTED] -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
[rsync-announce] rsync security advisory
rsync 2.5.6 security advisory - December 4th 2003 Background -- The rsync team has received evidence that a vulnerability in rsync was recently used in combination with a Linux kernel vulnerability to compromise the security of a public rsync server. While the forensic evidence we have is incomplete, we have pieced together the most likely way that this attack was conducted and we are releasing this advisory as a result of our investigations to date. Our conclusions are that: - rsync version 2.5.6 contains a heap overflow vulnerability that can be used to remotely run arbitrary code. - While this heap overflow vulnerability could not be used by itself to obtain root access on a rsync server, it could be used in combination with the recently announced brk vulnerability in the Linux kernel to produce a full remote compromise. - The server that was compromised was using a non-default rsyncd.conf option use chroot = no. The use of this option made the attack on the compromised server considerably easier. A successful attack is almost certainly still possible without this option, but it would be much more difficult. Please note that this vulnerability only affects the use of rsync as a rsync server. To see if you are running a rsync server you should use the netstat command to see if you are listening on TCP port 873. If you are not listening on TCP port 873 then you are not running a rsync server. New rsync release - In response we have released a new version of rsync, version 2.5.7. This is based on the current stable 2.5.6 release with only the changes necessary to prevent this heap overflow vulnerability. There are no new features in this release. We recommend that anyone running a rsync server take the following steps: 1) update to rsync version 2.5.7 immediately 2) if you are running a Linux kernel prior to version 2.4.23 then you should upgrade your kernel immediately. Note that some distribution vendors may have patched versions of the 2.4.x series kernel that fix the brk vulnerability in versions before 2.4.23. Check with your vendor security site to ensure that you are not vulnerable to the brk problem. 3) review your /etc/rsyncd.conf configuration file. If you are using the option use chroot = no then remove that line or change it to use chroot = yes. If you find that you need that option for your rsync service then you should disable your rsync service until you have discussed a workaround with the rsync maintainers on the rsync mailing list. The disabling of the chroot option should not be needed for any normal rsync server. The patches and full source for rsync version 2.5.7 are available from http://rsync.samba.org/ and mirror sites. We expect that vendors will produce updated packages for their distributions shortly. Credits --- The rsync team would like to thank the following individuals for their assistance in investigating this vulnerability and producing this response: * Timo Sirainen tss iki.fi * Mike Warfield mhw wittsend.com * Paul Russell rusty samba.org * Andrea Barisani lcars gentoo.org Regards, The rsync team signature.asc Description: Digital signature ___ rsync-announce mailing list [EMAIL PROTECTED] http://lists.samba.org/mailman/listinfo/rsync-announce
