From: Nicki Křížek Date: Tue, 3 Feb 2026 17:25:04 +0000 (+0100) Subject: Reproducer for CVE-2026-1519 X-Git-Tag: v9.21.20~5^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9bc14a89f1313aa38330e84674ac3b7691db3383;p=thirdparty%2Fbind9.git Reproducer for CVE-2026-1519 When a validating resolver processes a delegation from a DNSSEC-signed zone which uses too many NSEC3 iterations, it should cease the attempt to validate due to an NSEC3 iteration limit being exceeded and fall back to insecure. --- diff --git a/bin/tests/system/nsec3-delegation/ns1/named.conf.j2 b/bin/tests/system/nsec3-delegation/ns1/named.conf.j2 new file mode 100644 index 00000000000..65016d1c672 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns1/named.conf.j2 @@ -0,0 +1,35 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +options { + query-source address 10.53.0.1; + notify-source 10.53.0.1; + transfer-source 10.53.0.1; + port @PORT@; + pid-file "named.pid"; + listen-on { 10.53.0.1; }; + listen-on-v6 { none; }; + recursion no; + dnssec-validation no; +}; + +controls { + inet 10.53.0.1 port @CONTROLPORT@ allow { any; } keys { rndc_key; }; +}; + +include "../../_common/rndc.key"; + +zone "." { + type primary; + file "root.db"; +}; diff --git a/bin/tests/system/nsec3-delegation/ns1/root.db b/bin/tests/system/nsec3-delegation/ns1/root.db new file mode 100644 index 00000000000..c3f80d0d4b8 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns1/root.db @@ -0,0 +1,25 @@ +; Copyright (C) Internet Systems Consortium, Inc. ("ISC") +; +; SPDX-License-Identifier: MPL-2.0 +; +; This Source Code Form is subject to the terms of the Mozilla Public +; License, v. 2.0. If a copy of the MPL was not distributed with this +; file, you can obtain one at https://mozilla.org/MPL/2.0/. +; +; See the COPYRIGHT file distributed with this work for additional +; information regarding copyright ownership. + +$TTL 300 +. IN SOA . . ( + 2025063000 ; serial + 600 ; refresh + 600 ; retry + 1200 ; expire + 600 ; minimum + ) +. NS a.root-servers.nil. + +a.root-servers.nil A 10.53.0.1 + +iter-too-many. NS ns2.iter-too-many. +ns2.iter-too-many. A 10.53.0.2 diff --git a/bin/tests/system/nsec3-delegation/ns2/iter-too-many.db.j2.manual b/bin/tests/system/nsec3-delegation/ns2/iter-too-many.db.j2.manual new file mode 100644 index 00000000000..fa5023d21b9 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns2/iter-too-many.db.j2.manual @@ -0,0 +1,31 @@ +; Copyright (C) Internet Systems Consortium, Inc. ("ISC") +; +; SPDX-License-Identifier: MPL-2.0 +; +; This Source Code Form is subject to the terms of the Mozilla Public +; License, v. 2.0. If a copy of the MPL was not distributed with this +; file, you can obtain one at https://mozilla.org/MPL/2.0/. +; +; See the COPYRIGHT file distributed with this work for additional +; information regarding copyright ownership. + +{% raw %} +$TTL 300 +@ IN SOA ns2.iter-too-many. hostmaster.iter-too-many. ( + 2026020300 ; serial + 20 ; refresh (20 seconds) + 20 ; retry (20 seconds) + 1814400 ; expire (3 weeks) + 3600 ; minimum (1 hour) +) + +@ IN NS ns2.iter-too-many. +ns2 IN A 10.53.0.2 + +sub IN NS ns2.sub.iter-too-many. +ns2.sub IN A 10.53.0.2 +{% endraw %} + +{% for dnskey in dnskeys %} +@dnskey@ +{% endfor %} diff --git a/bin/tests/system/nsec3-delegation/ns2/named.conf.j2 b/bin/tests/system/nsec3-delegation/ns2/named.conf.j2 new file mode 100644 index 00000000000..2f4823574f1 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns2/named.conf.j2 @@ -0,0 +1,40 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +options { + query-source address 10.53.0.2; + notify-source 10.53.0.2; + transfer-source 10.53.0.2; + port @PORT@; + pid-file "named.pid"; + listen-on { 10.53.0.2; }; + listen-on-v6 { none; }; + recursion no; + dnssec-validation no; +}; + +controls { + inet 10.53.0.2 port @CONTROLPORT@ allow { any; } keys { rndc_key; }; +}; + +include "../../_common/rndc.key"; + +zone "iter-too-many" { + type primary; + file "iter-too-many.signed.db"; +}; + +zone "sub.iter-too-many" { + type primary; + file "sub.iter-too-many.db"; +}; diff --git a/bin/tests/system/nsec3-delegation/ns2/sub.iter-too-many.db b/bin/tests/system/nsec3-delegation/ns2/sub.iter-too-many.db new file mode 100644 index 00000000000..09b2bb6fb39 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns2/sub.iter-too-many.db @@ -0,0 +1,24 @@ +; Copyright (C) Internet Systems Consortium, Inc. ("ISC") +; +; SPDX-License-Identifier: MPL-2.0 +; +; This Source Code Form is subject to the terms of the Mozilla Public +; License, v. 2.0. If a copy of the MPL was not distributed with this +; file, you can obtain one at https://mozilla.org/MPL/2.0/. +; +; See the COPYRIGHT file distributed with this work for additional +; information regarding copyright ownership. + +$TTL 300 +@ IN SOA ns2.sub.iter-too-many. hostmaster.sub.iter-too-many. ( + 2026020300 ; serial + 20 ; refresh (20 seconds) + 20 ; retry (20 seconds) + 1814400 ; expire (3 weeks) + 3600 ; minimum (1 hour) +) + +@ IN NS ns2.sub.iter-too-many. +ns2 IN A 10.53.0.2 + +example IN A 127.0.0.1 diff --git a/bin/tests/system/nsec3-delegation/ns3/named.conf.j2 b/bin/tests/system/nsec3-delegation/ns3/named.conf.j2 new file mode 100644 index 00000000000..e36b88c53ea --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns3/named.conf.j2 @@ -0,0 +1,37 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +options { + query-source address 10.53.0.3; + notify-source 10.53.0.3; + transfer-source 10.53.0.3; + port @PORT@; + pid-file "named.pid"; + listen-on { 10.53.0.3; }; + listen-on-v6 { none; }; + recursion yes; + dnssec-validation yes; +}; + +controls { + inet 10.53.0.3 port @CONTROLPORT@ allow { any; } keys { rndc_key; }; +}; + +include "../../_common/rndc.key"; + +zone "." { + type hint; + file "../../_common/root.hint"; +}; + +include "trusted.conf"; diff --git a/bin/tests/system/nsec3-delegation/ns3/trusted.conf.j2 b/bin/tests/system/nsec3-delegation/ns3/trusted.conf.j2 new file mode 120000 index 00000000000..cb0be77b220 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/ns3/trusted.conf.j2 @@ -0,0 +1 @@ +../../_common/trusted.conf.j2 \ No newline at end of file diff --git a/bin/tests/system/nsec3-delegation/tests_excessive_nsec3_iterations.py b/bin/tests/system/nsec3-delegation/tests_excessive_nsec3_iterations.py new file mode 100644 index 00000000000..5bd17ed8743 --- /dev/null +++ b/bin/tests/system/nsec3-delegation/tests_excessive_nsec3_iterations.py @@ -0,0 +1,61 @@ +# Copyright (C) Internet Systems Consortium, Inc. ("ISC") +# +# SPDX-License-Identifier: MPL-2.0 +# +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, you can obtain one at https://mozilla.org/MPL/2.0/. +# +# See the COPYRIGHT file distributed with this work for additional +# information regarding copyright ownership. + +from isctest.run import EnvCmd + +import isctest + + +def bootstrap(): + templates = isctest.template.TemplateEngine(".") + keygen = EnvCmd("KEYGEN", "-a ECDSA256") + signer = EnvCmd("SIGNER") + + isctest.log.info("setup iter-too-many.") + zonename = "iter-too-many." + ksk_name = keygen(f"-f KSK {zonename}", cwd="ns2").out.strip() + zsk_name = keygen(f"{zonename}", cwd="ns2").out.strip() + ksk = isctest.kasp.Key(ksk_name, keydir="ns2") + zsk = isctest.kasp.Key(zsk_name, keydir="ns2") + dnskeys = [ksk.dnskey, zsk.dnskey] + + tdata = { + "dnskeys": dnskeys, + } + templates.render(f"ns2/{zonename}db", tdata, template=f"ns2/{zonename}db.j2.manual") + signer( + f"-P -o {zonename} -f {zonename}signed.db -3 A1B2C3D4 -H too-many -H 51 -S {zonename}db", + cwd="ns2", + ) + + return { + "trust_anchors": [ + ksk.into_ta("static-key"), + ], + } + + +def test_excessive_nsec3_iterations_delegation(ns3): + # reproducer for CVE-2026-1519 [GL#5708] + zone = "example.sub.iter-too-many" + msg = isctest.query.create(zone, "A") + res = isctest.query.tcp(msg, ns3.ip) + + # an insecure response is expected regardless of the NSEC3 iteration limit, + # because the sub.iter-too-many. zone is unsigned. the real difference is + # in the CPU usage required for generating such response, but that can't be + # easily and reliably tested in an automated fashion + isctest.check.noerror(res) + + with ns3.watch_log_from_start() as watcher: + watcher.wait_for_line( + f"validating {zone}/A: validator_callback_ds: too many iterations" + )