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58 lines
2.6 KiB
58 lines
2.6 KiB
# --- SDE-COPYRIGHT-NOTE-BEGIN --- |
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# This copyright note is auto-generated by ./scripts/Create-CopyPatch. |
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# |
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# Filename: package/.../djbdns/AXFR_vulnerability.patch |
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# Copyright (C) 2009 The OpenSDE Project |
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# |
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# More information can be found in the files COPYING and README. |
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# |
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# This patch file is dual-licensed. It is available under the license the |
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# patched project is licensed under, as long as it is an OpenSource license |
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# as defined at http://www.opensource.org/ (e.g. BSD, X11) or under the terms |
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# of the GNU General Public License as published by the Free Software |
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# Foundation; either version 2 of the License, or (at your option) any later |
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# version. |
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# --- SDE-COPYRIGHT-NOTE-END --- |
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Mailing-List: contact dns-help@list.cr.yp.to; run by ezmlm |
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Date: 4 Mar 2009 01:34:21 -0000 |
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Message-ID: <20090304013421.60368.qmail@cr.yp.to> |
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Mail-Followup-To: dns@list.cr.yp.to |
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Automatic-Legal-Notices: See http://cr.yp.to/mailcopyright.html. |
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From: "D. J. Bernstein" <djb@cr.yp.to> |
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To: dns@list.cr.yp.to |
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Subject: djbdns<=1.05 lets AXFRed subdomains overwrite domains |
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If the administrator of example.com publishes the example.com DNS data |
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through tinydns and axfrdns, and includes data for sub.example.com |
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transferred from an untrusted third party, then that third party can |
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control cache entries for example.com, not just sub.example.com. This is |
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the result of a bug in djbdns pointed out by Matthew Dempsky. (In short, |
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axfrdns compresses some outgoing DNS packets incorrectly.) |
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Even though this bug affects very few users, it is a violation of the |
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expected security policy in a reasonable situation, so it is a security |
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hole in djbdns. Third-party DNS service is discouraged in the djbdns |
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documentation but is nevertheless supported. Dempsky is hereby awarded |
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$1000. |
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The next release of djbdns will be backed by a new security guarantee. |
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In the meantime, if any users are in the situation described above, |
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those users are advised to apply Dempsky's patch and requested to accept |
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my apologies. The patch is also recommended for other users; it corrects |
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the bug without any side effects. A copy of the patch appears below. |
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---D. J. Bernstein |
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Research Professor, Computer Science, University of Illinois at Chicago |
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--- ./response.c.orig 2009-03-05 22:16:18.000000000 +0200 |
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+++ ./response.c 2009-03-05 22:16:57.000000000 +0200 |
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@@ -34,7 +34,7 @@ |
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uint16_pack_big(buf,49152 + name_ptr[i]); |
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return response_addbytes(buf,2); |
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} |
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- if (dlen <= 128) |
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+ if ((dlen <= 128) && (response_len < 16384)) |
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if (name_num < NAMES) { |
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byte_copy(name[name_num],dlen,d); |
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name_ptr[name_num] = response_len;
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