[patch] heimdal-7.1.0-CVE-2017-6594.patch

heimdal-7.1.0-CVE-2017-6594.patch (text/plain), 5.96 KB, created by Andrey Ovcharov on 2017-06-10 13:44:10 UTC

diff -ru NEWS NEWS
--- NEWS	2016-11-29 01:35:27.000000000 +0000
+++ NEWS	2017-06-03 15:23:36.264325000 +0000
@@ -1,4 +1,18 @@
-Release Notes - Heimdal - Version Heimdal 1.6
+Release Notes - Heimdal - Version Heimdal 7.1.0,2 (FreeBSD port)
+
+ Security
+
+ - Fix transit path validation.  Commit f469fc6 (2010-10-02) inadvertently
+   caused the previous hop realm to not be added to the transit path
+   of issued tickets.  This may, in some cases, enable bypass of capath
+   policy in Heimdal versions 1.5 through 7.2.
+
+   Note, this may break sites that rely on the bug.  With the bug some
+   incomplete [capaths] worked, that should not have.  These may now break
+   authentication in some cross-realm configurations.
+   (CVE-2017-6594)
+
+Release Notes - Heimdal - Version Heimdal 7.1
 
  Security
  - ...
diff -ru kdc/krb5tgs.c kdc/krb5tgs.c
--- kdc/krb5tgs.c	2016-11-29 01:35:27.000000000 +0000
+++ kdc/krb5tgs.c	2017-06-03 15:23:36.271738000 +0000
@@ -655,8 +655,12 @@
 		  "Decoding transited encoding");
 	return ret;
     }
+
+    /*
+     * If the realm of the presented tgt is neither the client nor the server
+     * realm, it is a transit realm and must be added to transited set.
+     */
     if(strcmp(client_realm, tgt_realm) && strcmp(server_realm, tgt_realm)) {
-	/* not us, so add the previous realm to transited set */
 	if (num_realms + 1 > UINT_MAX/sizeof(*realms)) {
 	    ret = ERANGE;
 	    goto free_realms;
@@ -737,6 +741,7 @@
 	       const char *server_name,
 	       hdb_entry_ex *client,
 	       krb5_principal client_principal,
+               const char *tgt_realm,
 	       hdb_entry_ex *krbtgt,
 	       krb5_enctype krbtgt_etype,
 	       krb5_principals spp,
@@ -798,7 +803,7 @@
 				 &tgt->transited, &et,
 				 krb5_principal_get_realm(context, client_principal),
 				 krb5_principal_get_realm(context, server->entry.principal),
-				 krb5_principal_get_realm(context, krbtgt->entry.principal));
+				 tgt_realm);
     if(ret)
 	goto out;
 
@@ -1519,6 +1524,8 @@
     krb5_keyblock sessionkey;
     krb5_kvno kvno;
     krb5_data rspac;
+    const char *tgt_realm = /* Realm of TGT issuer */
+        krb5_principal_get_realm(context, krbtgt->entry.principal);
     const char *our_realm = /* Realm of this KDC */
         krb5_principal_get_comp_string(context, krbtgt->entry.principal, 1);
     char **capath = NULL;
@@ -2324,6 +2331,7 @@
 			 spn,
 			 client,
 			 cp,
+                         tgt_realm,
 			 krbtgt_out,
 			 tkey_sign->key.keytype,
 			 spp,
diff -ru tests/kdc/check-kdc.in tests/kdc/check-kdc.in
--- tests/kdc/check-kdc.in	2016-12-14 18:01:18.000000000 +0000
+++ tests/kdc/check-kdc.in	2017-06-03 15:23:36.276571000 +0000
@@ -53,6 +53,7 @@
 R5=SOME-REALM5.FR
 R6=SOME-REALM6.US
 R7=SOME-REALM7.UK
+R8=SOME-REALM8.UK
 
 H1=H1.$R
 H2=H2.$R
@@ -152,6 +153,12 @@
     init \
     --realm-max-ticket-life=1day \
     --realm-max-renewable-life=1month \
+    ${R8} || exit 1
+
+${kadmin} \
+    init \
+    --realm-max-ticket-life=1day \
+    --realm-max-renewable-life=1month \
     ${H1} || exit 1
 
 ${kadmin} \
@@ -191,6 +198,7 @@
 ${kadmin5} add -p foo --use-defaults foo@${R5} || exit 1
 ${kadmin} add -p foo --use-defaults foo@${R6} || exit 1
 ${kadmin} add -p foo --use-defaults foo@${R7} || exit 1
+${kadmin} add -p foo --use-defaults foo@${R8} || exit 1
 ${kadmin} add -p foo --use-defaults foo@${H1} || exit 1
 ${kadmin} add -p foo --use-defaults foo/host.${h1}@${H1} || exit 1
 ${kadmin} add -p foo --use-defaults foo@${H2} || exit 1
@@ -249,6 +257,9 @@
 ${kadmin} add -p cross1 --use-defaults krbtgt/${R7}@${R6} || exit 1
 ${kadmin} add -p cross2 --use-defaults krbtgt/${R6}@${R7} || exit 1
 
+${kadmin} add -p cross1 --use-defaults krbtgt/${R8}@${R6} || exit 1
+${kadmin} add -p cross2 --use-defaults krbtgt/${R6}@${R8} || exit 1
+
 ${kadmin} add -p cross1 --use-defaults krbtgt/${H1}@${R} || exit 1
 ${kadmin} add -p cross2 --use-defaults krbtgt/${R}@${H1} || exit 1
 
@@ -284,6 +295,7 @@
 ${kadmin5} check ${R5} || exit 1
 ${kadmin} check ${R6} || exit 1
 ${kadmin} check ${R7} || exit 1
+${kadmin} check ${R8} || exit 1
 ${kadmin} check ${H1} || exit 1
 ${kadmin} check ${H2} || exit 1
 ${kadmin} check ${H3} || exit 1
@@ -388,6 +400,8 @@
 ${kgetcred} foo@${R6} || { ec=1 ; eval "${testfailed}"; }
 echo "Getting x-realm tickets with capaths for $R -> $R7"
 ${kgetcred} foo@${R7} || { ec=1 ; eval "${testfailed}"; }
+echo "Should not get x-realm tickets with capaths for $R -> $R8"
+${kgetcred} foo@${R8} && { ec=1 ; eval "${testfailed}"; }
 ${kdestroy}
 
 echo "Testing capaths logic (reverse order)"
@@ -418,10 +432,13 @@
 
 echo "Getting x-realm tickets with hierarchical referrals for $H3 -> $H1"
 ${kgetcred} --hostbased --canonicalize foo host.${h1} || { ec=1 ; eval "${testfailed}"; }
+fgrep "cross-realm ${H3} -> ${H1} via [${H2}, ${R}]" messages.log > /dev/null || { ec=1 ; eval "${testfailed}"; }
 echo "Getting x-realm tickets with hierarchical referrals for $H3 -> $R"
 ${kgetcred} --hostbased --canonicalize foo host.${r} || { ec=1 ; eval "${testfailed}"; }
+fgrep "cross-realm ${H3} -> ${R} via [${H2}]" messages.log > /dev/null || { ec=1 ; eval "${testfailed}"; }
 echo "Getting x-realm tickets with hierarchical referrals for $H3 -> $H2"
 ${kgetcred} --hostbased --canonicalize foo host.${h2} || { ec=1 ; eval "${testfailed}"; }
+fgrep "cross-realm ${H3} -> ${H2}" messages.log > /dev/null || { ec=1 ; eval "${testfailed}"; }
 ${kdestroy}
 
 echo "Testing multi-hop [capaths] referral logic"
diff -ru tests/kdc/krb5.conf.in tests/kdc/krb5.conf.in
--- tests/kdc/krb5.conf.in	2016-11-29 01:35:28.000000000 +0000
+++ tests/kdc/krb5.conf.in	2017-06-03 15:23:36.278848000 +0000
@@ -40,6 +40,9 @@
 	SOME-REALM7.UK = {
 		kdc = localhost:@port@
 	}
+	SOME-REALM8.UK = {
+		kdc = localhost:@port@
+	}
 	TEST-HTTP.H5L.SE = {
 		kdc = http/localhost:@port@
 	}
@@ -147,6 +150,7 @@
 		SOME-REALM6.US = SOME-REALM5.FR
 		SOME-REALM7.UK = SOME-REALM6.US
 		SOME-REALM7.UK = SOME-REALM5.FR
+		SOME-REALM8.UK = SOME-REALM6.US
 	}
         H4.H2.TEST.H5L.SE = {
                 H1.TEST.H5L.SE = H3.H2.TEST.H5L.SE