Read this yesterday. an upgrade seems in order. On Tuesday 25 June 2002 02:50 pm, Philip J. Koenig wrote: > There has been a heated discussion on this over in the FreeBSD > security list, suffice to say that Theo's obnoxious attitude doesn't > > help matters. Nonetheless this is important info: > > ----------- Forwarded message ------------ > > Date: Mon, 24 Jun 2002 15:00:10 -0600 > > From: Theo de Raadt <[EMAIL PROTECTED]> > > To: [EMAIL PROTECTED] > > Cc: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] > > Subject: Upcoming OpenSSH vulnerability > > > > There is an upcoming OpenSSH vulnerability that we're working on with > > ISS. > > Details will be published early next week. > > > > However, I can say that when OpenSSH's sshd(8) is running with priv > > seperation, the bug cannot be exploited. > > > > OpenSSH 3.3p was released a few days ago, with various improvements > > but in particular, it significantly improves the Linux and Solaris > > support for priv sep. However, it is not yet perfect. Compression is > > disabled on some systems, and the many varieties of PAM are causing > > major headaches. > > > > However, everyone should update to OpenSSH 3.3 immediately, and enable > > priv seperation in their ssh daemons, by setting this in your > > /etc/ssh/sshd_config file: > > > > UsePrivilegeSeparation yes > > > > Depending on what your system is, privsep may break some ssh > > functionality. However, with privsep turned on, you are immune from > > at least one remote hole. Understand? > > > > 3.3 does not contain a fix for this upcoming bug. > > > > If priv seperation does not work on your operating system, you need to > > work with your vendor so that we get patches to make it work on your > > system. Our developers are swamped enough without trying to support > > the myriad of PAM and other issues which exist in various systems. You > > must call on your vendors to help us. > > > > Basically, OpenSSH sshd(8) is something like 27000 lines of code. A > > lot of that runs as root. But when UsePrivilegeSeparation is enabled, > > the daemon splits into two parts. A part containing about 2500 lines > > of code remains as root, and the rest of the code is shoved into a > > chroot-jail without any privs. This makes the daemon less vulnerable > > to attack. > > > > We've been trying to warn vendors about 3.3 and the need for privsep, > > but they really have not heeded our call for assistance. They have > > basically ignored us. Some, like Alan Cox, even went further stating > > that privsep was not being worked on because "Nobody provided any info > > which proves the problem, and many people dont trust you theo" and > > suggested I "might be feeding everyone a trojan" (I think I'll publish > > that letter -- it is just so funny). HP's representative was > > downright rude, but that is OK because Compaq is retiring him. Except > > for Solar Designer, I think none of them has helped the OpenSSH > > portable developers make privsep work better on their systems. > > Apparently Solar Designer is the only person who understands the need > > for this stuff. > > > > So, if vendors would JUMP and get it working better, and send us > > patches IMMEDIATELY, we can perhaps make a 3.3.1p release on Friday > > which supports these systems better. So send patches by Thursday > > night please. Then on Tuesday or Wednesday the complete bug report > > with patches (and exploits soon after I am sure) will hit BUGTRAQ. > > > > Let me repeat: even if the bug exists in a privsep'd sshd, it is not > > exploitable. Clearly we cannot yet publish what the bug is, or > > provide anyone with the real patch, but we can try to get maximum > > deployement of privsep, and therefore make it hurt less when the > > problem is published. > > > > So please push your vendor to get us maximally working privsep patches > > as soon as possible! > > > > We've given most vendors since Friday last week until Thursday to get > > privsep working well for you so that when the announcement comes out > > next week their customers are immunized. That is nearly a full week > > (but they have already wasted a weekend and a Monday). Really I think > > this is the best we can hope to do (this thing will eventually leak, > > at which point the details will be published). > > > > Customers can judge their vendors by how they respond to this issue. > > > > OpenBSD and NetBSD users should also update to OpenSSH 3.3 right away. > > On OpenBSD privsep works flawlessly, and I have reports that is also > > true on NetBSD. All other systems appear to have minor or major > > weaknesses when this code is running. > > > > (securityfocus postmaster; please post this through immediately, since > > i have bcc'd over 30 other places..)
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