From ad377f82ce7ab1a364d456ff7783e2a43eff23a0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= Date: Thu, 18 Jul 2024 17:24:18 +0200 Subject: [PATCH] Resolve CVE-2024-1975 6404. [security] Remove SIG(0) support from named as a countermeasure for CVE-2024-1975. [GL #4480] Resolves: RHEL-50350 --- bind-9.16-CVE-2024-1975.patch | 318 ++++++++++++++++++++++++++++++++++ bind.spec | 7 +- 2 files changed, 324 insertions(+), 1 deletion(-) create mode 100644 bind-9.16-CVE-2024-1975.patch diff --git a/bind-9.16-CVE-2024-1975.patch b/bind-9.16-CVE-2024-1975.patch new file mode 100644 index 0000000..def3ed4 --- /dev/null +++ b/bind-9.16-CVE-2024-1975.patch @@ -0,0 +1,318 @@ +From 34e92fc88943beeba76aa4e408951cb46d8cdb53 Mon Sep 17 00:00:00 2001 +From: Petr Mensik +Date: Tue, 16 Jul 2024 19:49:09 +0200 +Subject: [PATCH] Resolve CVE-2024-1975 + +6404. [security] Remove SIG(0) support from named as a countermeasure + for CVE-2024-1975. [GL #4480] + +Resolves: CVE-2024-1975 +--- + bin/tests/system/tsiggss/authsock.pl | 5 ++ + bin/tests/system/tsiggss/tests.sh | 12 ++-- + bin/tests/system/upforwd/tests.sh | 21 +++--- + doc/arm/general.rst | 6 +- + doc/arm/reference.rst | 4 +- + doc/arm/security.rst | 4 +- + lib/dns/message.c | 97 ++-------------------------- + lib/ns/client.c | 7 ++ + 8 files changed, 43 insertions(+), 113 deletions(-) + +diff --git a/bin/tests/system/tsiggss/authsock.pl b/bin/tests/system/tsiggss/authsock.pl +index ab3833d..0b231ee 100644 +--- a/bin/tests/system/tsiggss/authsock.pl ++++ b/bin/tests/system/tsiggss/authsock.pl +@@ -31,6 +31,10 @@ if (!defined($path)) { + exit(1); + } + ++# Enable output autoflush so that it's not lost when the parent sends TERM. ++select STDOUT; ++$| = 1; ++ + unlink($path); + my $server = IO::Socket::UNIX->new(Local => $path, Type => SOCK_STREAM, Listen => 8) or + die "unable to create socket $path"; +@@ -53,6 +57,7 @@ if ($timeout != 0) { + } + + while (my $client = $server->accept()) { ++ printf("accept()\n"); + $client->recv(my $buf, 8, 0); + my ($version, $req_len) = unpack('N N', $buf); + +diff --git a/bin/tests/system/tsiggss/tests.sh b/bin/tests/system/tsiggss/tests.sh +index 632bb87..7977e49 100644 +--- a/bin/tests/system/tsiggss/tests.sh ++++ b/bin/tests/system/tsiggss/tests.sh +@@ -116,7 +116,7 @@ status=$((status+ret)) + + echo_i "testing external update policy (CNAME) with auth sock ($n)" + ret=0 +-$PERL ./authsock.pl --type=CNAME --path=ns1/auth.sock --pidfile=authsock.pid --timeout=120 > /dev/null 2>&1 & ++$PERL ./authsock.pl --type=CNAME --path=ns1/auth.sock --pidfile=authsock.pid --timeout=120 >authsock.log 2>&1 & + sleep 1 + test_update $n testcname.example.nil. CNAME "86400 CNAME testdenied.example.nil" "testdenied" || ret=1 + n=$((n+1)) +@@ -130,17 +130,19 @@ n=$((n+1)) + if [ "$ret" -ne 0 ]; then echo_i "failed"; fi + status=$((status+ret)) + +-echo_i "testing external policy with SIG(0) key ($n)" ++echo_i "testing external policy with unsupported SIG(0) key ($n)" + ret=0 +-$NSUPDATE -k ns1/Kkey.example.nil.*.private < /dev/null 2>&1 || ret=1 ++$NSUPDATE -d -k ns1/Kkey.example.nil.*.private <nsupdate.out${n} 2>&1 || true ++debug + server 10.53.0.1 ${PORT} + zone example.nil + update add fred.example.nil 120 cname foo.bar. + send + END + output=`$DIG $DIGOPTS +short cname fred.example.nil.` +-[ -n "$output" ] || ret=1 +-[ $ret -eq 0 ] || echo_i "failed" ++# update must have failed - SIG(0) signer is not supported ++[ -n "$output" ] && ret=1 ++grep -F "signer=key.example.nil" authsock.log >/dev/null && ret=1 + n=$((n+1)) + if [ "$ret" -ne 0 ]; then echo_i "failed"; fi + status=$((status+ret)) +diff --git a/bin/tests/system/upforwd/tests.sh b/bin/tests/system/upforwd/tests.sh +index 20fc46f..c8fd54b 100644 +--- a/bin/tests/system/upforwd/tests.sh ++++ b/bin/tests/system/upforwd/tests.sh +@@ -224,19 +224,22 @@ fi + + if test -f keyname + then +- echo_i "checking update forwarding to with sig0 ($n)" ++ echo_i "checking update forwarding to with sig0 (expected to fail) ($n)" + ret=0 + keyname=`cat keyname` +- $NSUPDATE -k $keyname.private -- - <nsupdate.out.$n 2>&1 && ret=1 + $DIG -p ${PORT} unsigned.example2 A @10.53.0.1 > dig.out.ns1.test$n +- grep "status: NOERROR" dig.out.ns1.test$n > /dev/null || ret=1 ++ grep "status: NOERROR" dig.out.ns1.test$n >/dev/null && ret=1 + if [ $ret != 0 ] ; then echo_i "failed"; fi + status=`expr $status + $ret` + n=`expr $n + 1` +diff --git a/doc/arm/general.rst b/doc/arm/general.rst +index 225576b..0766dfe 100644 +--- a/doc/arm/general.rst ++++ b/doc/arm/general.rst +@@ -534,10 +534,8 @@ than a non-authoritative response. This is considered a feature. + [2] CLASS ANY queries are not supported. This is considered a + feature. + +-[3] When receiving a query signed with a SIG(0), the server is +-only able to verify the signature if it has the key in its local +-authoritative data; it cannot do recursion or validation to +-retrieve unknown keys. ++[3] Support for SIG(0) message verification was removed ++as part of the mitigation of CVE-2024-1975. + + [4] Compliance is with loading and serving of A6 records only. A6 records were moved + to the experimental category by :rfc:`3363`. +diff --git a/doc/arm/reference.rst b/doc/arm/reference.rst +index d4ee9d2..ad7ff27 100644 +--- a/doc/arm/reference.rst ++++ b/doc/arm/reference.rst +@@ -5789,7 +5789,7 @@ The ``update-policy`` clause allows more fine-grained control over which + updates are allowed. It specifies a set of rules, in which each rule + either grants or denies permission for one or more names in the zone to + be updated by one or more identities. Identity is determined by the key +-that signed the update request, using either TSIG or SIG(0). In most ++that signed the update request, using either TSIG. In most + cases, ``update-policy`` rules only apply to key-based identities. There + is no way to specify update permissions based on the client source address. + +@@ -5846,7 +5846,7 @@ field), and the type of the record to be updated matches the ``types`` + field. Details for each rule type are described below. + + The ``identity`` field must be set to a fully qualified domain name. In +-most cases, this represents the name of the TSIG or SIG(0) key that ++most cases, this represents the name of the TSIG key that + must be used to sign the update request. If the specified name is a + wildcard, it is subject to DNS wildcard expansion, and the rule may + apply to multiple identities. When a TKEY exchange has been used to +diff --git a/doc/arm/security.rst b/doc/arm/security.rst +index f7c8bd3..e3abfd1 100644 +--- a/doc/arm/security.rst ++++ b/doc/arm/security.rst +@@ -32,7 +32,7 @@ Limiting access to the server by outside parties can help prevent + spoofing and denial of service (DoS) attacks against the server. + + ACLs match clients on the basis of up to three characteristics: 1) The +-client's IP address; 2) the TSIG or SIG(0) key that was used to sign the ++client's IP address; 2) the TSIG key that was used to sign the + request, if any; and 3) an address prefix encoded in an EDNS + Client-Subnet option, if any. + +@@ -73,7 +73,7 @@ and no queries at all from the networks specified in ``bogusnets``. + + In addition to network addresses and prefixes, which are matched against + the source address of the DNS request, ACLs may include ``key`` +-elements, which specify the name of a TSIG or SIG(0) key. ++elements, which specify the name of a TSIG key. + + When BIND 9 is built with GeoIP support, ACLs can also be used for + geographic access restrictions. This is done by specifying an ACL +diff --git a/lib/dns/message.c b/lib/dns/message.c +index 1993b2e..04315bc 100644 +--- a/lib/dns/message.c ++++ b/lib/dns/message.c +@@ -3287,109 +3287,24 @@ dns_message_dumpsig(dns_message_t *msg, char *txt1) { + + isc_result_t + dns_message_checksig(dns_message_t *msg, dns_view_t *view) { +- isc_buffer_t b, msgb; ++ isc_buffer_t msgb; + + REQUIRE(DNS_MESSAGE_VALID(msg)); + +- if (msg->tsigkey == NULL && msg->tsig == NULL && msg->sig0 == NULL) { ++ if (msg->tsigkey == NULL && msg->tsig == NULL) { + return (ISC_R_SUCCESS); + } + + INSIST(msg->saved.base != NULL); + isc_buffer_init(&msgb, msg->saved.base, msg->saved.length); + isc_buffer_add(&msgb, msg->saved.length); +- if (msg->tsigkey != NULL || msg->tsig != NULL) { + #ifdef SKAN_MSG_DEBUG +- dns_message_dumpsig(msg, "dns_message_checksig#1"); ++ dns_message_dumpsig(msg, "dns_message_checksig#1"); + #endif /* ifdef SKAN_MSG_DEBUG */ +- if (view != NULL) { +- return (dns_view_checksig(view, &msgb, msg)); +- } else { +- return (dns_tsig_verify(&msgb, msg, NULL, NULL)); +- } ++ if (view != NULL) { ++ return (dns_view_checksig(view, &msgb, msg)); + } else { +- dns_rdata_t rdata = DNS_RDATA_INIT; +- dns_rdata_sig_t sig; +- dns_rdataset_t keyset; +- isc_result_t result; +- +- result = dns_rdataset_first(msg->sig0); +- INSIST(result == ISC_R_SUCCESS); +- dns_rdataset_current(msg->sig0, &rdata); +- +- /* +- * This can occur when the message is a dynamic update, since +- * the rdata length checking is relaxed. This should not +- * happen in a well-formed message, since the SIG(0) is only +- * looked for in the additional section, and the dynamic update +- * meta-records are in the prerequisite and update sections. +- */ +- if (rdata.length == 0) { +- return (ISC_R_UNEXPECTEDEND); +- } +- +- result = dns_rdata_tostruct(&rdata, &sig, msg->mctx); +- if (result != ISC_R_SUCCESS) { +- return (result); +- } +- +- dns_rdataset_init(&keyset); +- if (view == NULL) { +- return (DNS_R_KEYUNAUTHORIZED); +- } +- result = dns_view_simplefind(view, &sig.signer, +- dns_rdatatype_key /* SIG(0) */, 0, +- 0, false, &keyset, NULL); +- +- if (result != ISC_R_SUCCESS) { +- /* XXXBEW Should possibly create a fetch here */ +- result = DNS_R_KEYUNAUTHORIZED; +- goto freesig; +- } else if (keyset.trust < dns_trust_secure) { +- /* XXXBEW Should call a validator here */ +- result = DNS_R_KEYUNAUTHORIZED; +- goto freesig; +- } +- result = dns_rdataset_first(&keyset); +- INSIST(result == ISC_R_SUCCESS); +- for (; result == ISC_R_SUCCESS; +- result = dns_rdataset_next(&keyset)) { +- dst_key_t *key = NULL; +- +- dns_rdata_reset(&rdata); +- dns_rdataset_current(&keyset, &rdata); +- isc_buffer_init(&b, rdata.data, rdata.length); +- isc_buffer_add(&b, rdata.length); +- +- result = dst_key_fromdns(&sig.signer, rdata.rdclass, &b, +- view->mctx, &key); +- if (result != ISC_R_SUCCESS) { +- continue; +- } +- if (dst_key_alg(key) != sig.algorithm || +- dst_key_id(key) != sig.keyid || +- !(dst_key_proto(key) == DNS_KEYPROTO_DNSSEC || +- dst_key_proto(key) == DNS_KEYPROTO_ANY)) +- { +- dst_key_free(&key); +- continue; +- } +- result = dns_dnssec_verifymessage(&msgb, msg, key); +- dst_key_free(&key); +- if (result == ISC_R_SUCCESS) { +- break; +- } +- } +- if (result == ISC_R_NOMORE) { +- result = DNS_R_KEYUNAUTHORIZED; +- } +- +- freesig: +- if (dns_rdataset_isassociated(&keyset)) { +- dns_rdataset_disassociate(&keyset); +- } +- dns_rdata_freestruct(&sig); +- return (result); ++ return (dns_tsig_verify(&msgb, msg, NULL, NULL)); + } + } + +diff --git a/lib/ns/client.c b/lib/ns/client.c +index 967e21b..87b8a18 100644 +--- a/lib/ns/client.c ++++ b/lib/ns/client.c +@@ -2060,6 +2060,13 @@ ns__client_request(isc_nmhandle_t *handle, isc_result_t eresult, + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "request is signed by a nonauthoritative key"); ++ } else if (result == DNS_R_NOTVERIFIEDYET && ++ client->message->sig0 != NULL) ++ { ++ ns_client_log(client, DNS_LOGCATEGORY_SECURITY, ++ NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), ++ "request has a SIG(0) signature but its support " ++ "was removed (CVE-2024-1975)"); + } else { + char tsigrcode[64]; + isc_buffer_t b; +-- +2.45.2 + diff --git a/bind.spec b/bind.spec index d2f0500..99c5c3c 100644 --- a/bind.spec +++ b/bind.spec @@ -51,7 +51,7 @@ Summary: The Berkeley Internet Name Domain (BIND) DNS (Domain Name System) serv Name: bind License: MPLv2.0 Version: 9.16.23 -Release: 21%{?dist} +Release: 22%{?dist} Epoch: 32 Url: https://www.isc.org/downloads/bind/ # @@ -153,6 +153,7 @@ Patch203: bind-9.16-isc_hp-CVE-2023-50387.patch # https://gitlab.isc.org/isc-projects/bind9/commit/1237d73cd1120b146ee699bbae7b2fe837cf2f98 Patch204: bind-9.16-CVE-2023-6516-test.patch Patch205: bind-9.16-isc_hp-additional.patch +Patch206: bind-9.16-CVE-2024-1975.patch %{?systemd_ordering} Requires: coreutils @@ -490,6 +491,7 @@ in HTML and PDF format. %patch203 -p1 -b .isc_hp-CVE-2023-50387 %patch204 -p1 -b .CVE-2023-6516-test %patch205 -p1 -b .RHEL-39131 +%patch206 -p1 -b .CVE-2024-1975 %if %{with PKCS11} %patch135 -p1 -b .config-pkcs11 @@ -1218,6 +1220,9 @@ fi; %endif %changelog +* Thu Jul 18 2024 Petr Menšík - 32:9.16.23-22 +- Resolve CVE-2024-1975 + * Tue Jul 09 2024 Petr Menšík - 32:9.16.23-21 - Increase size of hazard pointer array (RHEL-39131)