[v9_9_10_patch] address TSIG bypass/forgery vulnerabilities

4643.	[security]	An error in TSIG handling could permit unauthorized
                    zone transfers or zone updates. (CVE-2017-3142)
                    (CVE-2017-3143) [RT #45383]

diff --git a/CHANGES b/CHANGES
index e7230caed538c812aa7c80a28ecf36e58d606ae2..07e13f226fa77dbf81159dd8f2e0d760038eebd5 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,9 @@
+       --- 9.9.10-P2 released ---
+
+4643.  [security]      An error in TSIG handling could permit unauthorized
+                       zone transfers or zone updates. (CVE-2017-3142)
+                       (CVE-2017-3143) [RT #45383]
+
 4633.  [maint]         Updated AAAA (2001:500:200::b) for B.ROOT-SERVERS.NET.
 
        --- 9.9.10-P1 released ---

diff --git a/README b/README
index 47e03d7e40ce12e82e6e35ca7635bcc9acf61d5b..596f436da65496b34b1366c9b74259826fd74c94 100644 (file)
--- a/README
+++ b/README
@@ -51,6 +51,11 @@ BIND 9
        For up-to-date release notes and errata, see
        http://www.isc.org/software/bind9/releasenotes
 
+BIND 9.9.10-P2
+
+        This version contains a fix for the security flaws
+        disclosed in CVE-2017-3142 and CVE-2017-3143.
+
 BIND 9.9.10-P1
 
         This version contains a fix for the security flaws

diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
index 98edd1b288f6cc3650e4d54c2ee529ef3bad3375..946d8c45a996c404e3cb65c483ec156377fd1697 100644 (file)
--- a/doc/arm/notes.xml
+++ b/doc/arm/notes.xml
@@ -27,7 +27,11 @@
       BIND 9.9.10-P1 addresses the security issues described in
       CVE-2017-3140 and CVE-2017-3141.
     </para>
-
+    <para>
+      BIND 9.9.10-P2 addresses the security issues described in
+      CVE-2017-3142 and CVE-2017-3143. It also includes an update
+      to the address of the B root server.
+    </para>
   </section>
 
 
@@ -72,6 +76,13 @@
 
   <section xml:id="relnotes_security"><info><title>Security Fixes</title></info>
     <itemizedlist>
+      <listitem>
+       <para>
+         An error in TSIG handling could permit unauthorized zone
+         transfers or zone updates. These flaws are disclosed in
+         CVE-2017-3142 and CVE-2017-3143. [RT #45383]
+       </para>
+      </listitem>
       <listitem>
        <para>
          The BIND installer on Windows used an unquoted service path,

diff --git a/lib/dns/api b/lib/dns/api
index f833991e7713f8ec7840fcd108165342e67c04a6..d4285640528d8a151a732e54c1129b55275a6d32 100644 (file)
--- a/lib/dns/api
+++ b/lib/dns/api
@@ -7,5 +7,5 @@
 # 9.10: 140-149, 170-179
 # 9.11: 160-169
 LIBINTERFACE = 173
-LIBREVISION = 2
+LIBREVISION = 3
 LIBAGE = 0

diff --git a/lib/dns/dnssec.c b/lib/dns/dnssec.c
index a9bcd585e47f56ce85e7e6302d4df8f6025167d5..29af9837c2c30d3e5831a06722499a05b67abbf4 100644 (file)
--- a/lib/dns/dnssec.c
+++ b/lib/dns/dnssec.c
@@ -976,6 +976,8 @@ dns_dnssec_verifymessage(isc_buffer_t *source, dns_message_t *msg,
        mctx = msg->mctx;
 
        msg->verify_attempted = 1;
+       msg->verified_sig = 0;
+       msg->sig0status = dns_tsigerror_badsig;
 
        if (is_response(msg)) {
                if (msg->query.base == NULL)
@@ -1070,6 +1072,7 @@ dns_dnssec_verifymessage(isc_buffer_t *source, dns_message_t *msg,
        }
 
        msg->verified_sig = 1;
+       msg->sig0status = dns_rcode_noerror;
 
        dst_context_destroy(&ctx);
        dns_rdata_freestruct(&sig);

diff --git a/lib/dns/message.c b/lib/dns/message.c
index 5c7ca2067f1bdebc95f4d70d5e49539f609f2d43..5f03ec88f31636ef34fc3fe53c7c37da42146f73 100644 (file)
--- a/lib/dns/message.c
+++ b/lib/dns/message.c
@@ -3052,12 +3052,19 @@ dns_message_signer(dns_message_t *msg, dns_name_t *signer) {
 
                result = dns_rdata_tostruct(&rdata, &tsig, NULL);
                INSIST(result == ISC_R_SUCCESS);
-               if (msg->tsigstatus != dns_rcode_noerror)
+               if (msg->verified_sig &&
+                   msg->tsigstatus == dns_rcode_noerror &&
+                   tsig.error == dns_rcode_noerror)
+               {
+                       result = ISC_R_SUCCESS;
+               } else if ((!msg->verified_sig) ||
+                          (msg->tsigstatus != dns_rcode_noerror))
+               {
                        result = DNS_R_TSIGVERIFYFAILURE;
-               else if (tsig.error != dns_rcode_noerror)
+               } else {
+                       INSIST(tsig.error != dns_rcode_noerror);
                        result = DNS_R_TSIGERRORSET;
-               else
-                       result = ISC_R_SUCCESS;
+               }
                dns_rdata_freestruct(&tsig);
 
                if (msg->tsigkey == NULL) {

diff --git a/lib/dns/tsig.c b/lib/dns/tsig.c
index fea66a7cccd2448b132b9a6afa6f2708b688e994..4ea6259439d5de63369aa4f48dcd549a61748a7c 100644 (file)
--- a/lib/dns/tsig.c
+++ b/lib/dns/tsig.c
@@ -954,9 +954,10 @@ dns_tsig_sign(dns_message_t *msg) {
                        return (ret);
 
                /*
-                * If this is a response, digest the query signature.
+                * If this is a response and the query's signature
+                * validated, digest the query signature.
                 */
-               if (response) {
+               if (response && (tsig.error == dns_rcode_noerror)) {
                        dns_rdata_t querytsigrdata = DNS_RDATA_INIT;
 
                        ret = dns_rdataset_first(msg->querytsig);
@@ -1194,6 +1195,8 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
        REQUIRE(tsigkey == NULL || VALID_TSIG_KEY(tsigkey));
 
        msg->verify_attempted = 1;
+       msg->verified_sig = 0;
+       msg->tsigstatus = dns_tsigerror_badsig;
 
        if (msg->tcp_continuation) {
                if (tsigkey == NULL || msg->querytsig == NULL)
@@ -1313,27 +1316,31 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
                return (ret);
        if (alg == DST_ALG_HMACMD5 || alg == DST_ALG_HMACSHA1 ||
            alg == DST_ALG_HMACSHA224 || alg == DST_ALG_HMACSHA256 ||
-           alg == DST_ALG_HMACSHA384 || alg == DST_ALG_HMACSHA512) {
+           alg == DST_ALG_HMACSHA384 || alg == DST_ALG_HMACSHA512)
+       {
                isc_uint16_t digestbits = dst_key_getbits(key);
                if (tsig.siglen > siglen) {
                        tsig_log(msg->tsigkey, 2, "signature length too big");
                        return (DNS_R_FORMERR);
                }
                if (tsig.siglen > 0 &&
-                   (tsig.siglen < 10 || tsig.siglen < ((siglen + 1) / 2))) {
+                   (tsig.siglen < 10 || tsig.siglen < ((siglen + 1) / 2)))
+               {
                        tsig_log(msg->tsigkey, 2,
                                 "signature length below minimum");
                        return (DNS_R_FORMERR);
                }
                if (tsig.siglen > 0 && digestbits != 0 &&
-                   tsig.siglen < ((digestbits + 1) / 8)) {
+                   tsig.siglen < ((digestbits + 1) / 8))
+               {
                        msg->tsigstatus = dns_tsigerror_badtrunc;
                        tsig_log(msg->tsigkey, 2,
                                 "truncated signature length too small");
                        return (DNS_R_TSIGVERIFYFAILURE);
                }
                if (tsig.siglen > 0 && digestbits == 0 &&
-                   tsig.siglen < siglen) {
+                   tsig.siglen < siglen)
+               {
                        msg->tsigstatus = dns_tsigerror_badtrunc;
                        tsig_log(msg->tsigkey, 2, "signature length too small");
                        return (DNS_R_TSIGVERIFYFAILURE);
@@ -1351,7 +1358,7 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
                if (ret != ISC_R_SUCCESS)
                        return (ret);
 
-               if (response) {
+               if (response && (tsig.error == dns_rcode_noerror)) {
                        isc_buffer_init(&databuf, data, sizeof(data));
                        isc_buffer_putuint16(&databuf, querytsig.siglen);
                        isc_buffer_usedregion(&databuf, &r);
@@ -1456,10 +1463,9 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
                        tsig_log(msg->tsigkey, 2,
                                 "signature failed to verify(1)");
                        goto cleanup_context;
-               } else if (ret != ISC_R_SUCCESS)
+               } else if (ret != ISC_R_SUCCESS) {
                        goto cleanup_context;
-
-               dst_context_destroy(&ctx);
+               }
        } else if (tsig.error != dns_tsigerror_badsig &&
                   tsig.error != dns_tsigerror_badkey) {
                msg->tsigstatus = dns_tsigerror_badsig;
@@ -1467,18 +1473,18 @@ dns_tsig_verify(isc_buffer_t *source, dns_message_t *msg,
                return (DNS_R_TSIGVERIFYFAILURE);
        }
 
-       msg->tsigstatus = dns_rcode_noerror;
-
        if (tsig.error != dns_rcode_noerror) {
+               msg->tsigstatus = tsig.error;
                if (tsig.error == dns_tsigerror_badtime)
-                       return (DNS_R_CLOCKSKEW);
+                       ret = DNS_R_CLOCKSKEW;
                else
-                       return (DNS_R_TSIGERRORSET);
+                       ret = DNS_R_TSIGERRORSET;
+               goto cleanup_context;
        }
 
+       msg->tsigstatus = dns_rcode_noerror;
        msg->verified_sig = 1;
-
-       return (ISC_R_SUCCESS);
+       ret = ISC_R_SUCCESS;
 
 cleanup_context:
        if (ctx != NULL)
@@ -1510,6 +1516,9 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
        REQUIRE(msg->tcp_continuation == 1);
        REQUIRE(msg->querytsig != NULL);
 
+       msg->verified_sig = 0;
+       msg->tsigstatus = dns_tsigerror_badsig;
+
        if (!is_response(msg))
                return (DNS_R_EXPECTEDRESPONSE);
 
@@ -1548,7 +1557,8 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
                 * Do the key name and algorithm match that of the query?
                 */
                if (!dns_name_equal(keyname, &tsigkey->name) ||
-                   !dns_name_equal(&tsig.algorithm, &querytsig.algorithm)) {
+                   !dns_name_equal(&tsig.algorithm, &querytsig.algorithm))
+               {
                        msg->tsigstatus = dns_tsigerror_badkey;
                        ret = DNS_R_TSIGVERIFYFAILURE;
                        tsig_log(msg->tsigkey, 2,
@@ -1567,7 +1577,8 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
                        ret = DNS_R_CLOCKSKEW;
                        goto cleanup_querystruct;
                } else if (now + msg->timeadjust <
-                          tsig.timesigned - tsig.fudge) {
+                          tsig.timesigned - tsig.fudge)
+               {
                        msg->tsigstatus = dns_tsigerror_badtime;
                        tsig_log(msg->tsigkey, 2,
                                 "signature is in the future");
@@ -1673,10 +1684,12 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
                sig_r.length = tsig.siglen;
                if (tsig.siglen == 0) {
                        if (tsig.error != dns_rcode_noerror) {
-                               if (tsig.error == dns_tsigerror_badtime)
+                               msg->tsigstatus = tsig.error;
+                               if (tsig.error == dns_tsigerror_badtime) {
                                        ret = DNS_R_CLOCKSKEW;
-                               else
+                               } else {
                                        ret = DNS_R_TSIGERRORSET;
+                               }
                        } else {
                                tsig_log(msg->tsigkey, 2,
                                         "signature is empty");
@@ -1692,24 +1705,32 @@ tsig_verify_tcp(isc_buffer_t *source, dns_message_t *msg) {
                                 "signature failed to verify(2)");
                        ret = DNS_R_TSIGVERIFYFAILURE;
                        goto cleanup_context;
-               }
-               else if (ret != ISC_R_SUCCESS)
+               } else if (ret != ISC_R_SUCCESS) {
                        goto cleanup_context;
+               }
 
-               dst_context_destroy(&msg->tsigctx);
+               if (tsig.error != dns_rcode_noerror) {
+                       msg->tsigstatus = tsig.error;
+                       if (tsig.error == dns_tsigerror_badtime)
+                               ret = DNS_R_CLOCKSKEW;
+                       else
+                               ret = DNS_R_TSIGERRORSET;
+                       goto cleanup_context;
+               }
        }
 
        msg->tsigstatus = dns_rcode_noerror;
-       return (ISC_R_SUCCESS);
+       msg->verified_sig = 1;
+       ret = ISC_R_SUCCESS;
 
  cleanup_context:
-       dst_context_destroy(&msg->tsigctx);
+       if (msg->tsigctx != NULL)
+               dst_context_destroy(&msg->tsigctx);
 
  cleanup_querystruct:
        dns_rdata_freestruct(&querytsig);
 
        return (ret);
-
 }
 
 isc_result_t

diff --git a/version b/version
index 87fac20d2d8b78433c298f1f447fc3dca7b497c6..cb6e54d1d65fbf4f63b21e43bd4948f6511ebf84 100644 (file)
--- a/version
+++ b/version
@@ -7,5 +7,5 @@ MAJORVER=9
 MINORVER=9
 PATCHVER=10
 RELEASETYPE=-P
-RELEASEVER=1
+RELEASEVER=2
 EXTENSIONS=