diff --git a/CHANGELOG.md b/CHANGELOG.md
index a07304b6..6688e676 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,29 @@
 CHANGELOG
 =========
 
+v0.43 (September 1, 2019)
+-------------------------
+
+Security fixes:
+
+* A security issue was discovered in rsync backups. If you have enabled rsync backups, the file `id_rsa_miab` may have been copied to your backup destination. This file can be used to access your backup destination. If the file was copied to your backup destination, we recommend that you delete the file on your backup destination, delete `/root/.ssh/id_rsa_miab` on your Mail-in-a-Box, then re-run Mail-in-a-Box setup, and re-configure your SSH public key at your backup destination according to the instructions in the Mail-in-a-Box control panel.
+* Brute force attack prevention was missing for the managesieve service.
+
+Setup:
+
+* Nextcloud was not upgraded properly after restoring Mail-in-a-Box from a backup from v0.40 or earlier.
+
+Mail:
+
+* Upgraded Roundcube to 1.3.10.
+* Fetch an updated whitelist for greylisting on a monthly basis to reduce the number of delayed incoming emails.
+
+Control panel:
+
+* When using secondary DNS, it is now possible to specify a subnet range with the `xfr:` option.
+* Fixed an issue when the secondary DNS option is used and the secondary DNS hostname resolves to multiple IP addresses.
+* Fix a bug in how a backup configuration error is shown.
+
 v0.42b (August 3, 2019)
 -----------------------
 
diff --git a/README.md b/README.md
index 79e57083..4582f59c 100644
--- a/README.md
+++ b/README.md
@@ -202,7 +202,7 @@ by him:
 	$ curl -s https://keybase.io/joshdata/key.asc | gpg --import
 	gpg: key C10BDD81: public key "Joshua Tauberer <jt@occams.info>" imported
 
-	$ git verify-tag v0.42b
+	$ git verify-tag v0.43
 	gpg: Signature made ..... using RSA key ID C10BDD81
 	gpg: Good signature from "Joshua Tauberer <jt@occams.info>"
 	gpg: WARNING: This key is not certified with a trusted signature!
@@ -215,7 +215,7 @@ and on his [personal homepage](https://razor.occams.info/). (Of course, if this
 
 Checkout the tag corresponding to the most recent release:
 
-	$ git checkout v0.42b
+	$ git checkout v0.43
 
 Begin the installation.
 
diff --git a/conf/fail2ban/filter.d/dovecotimap.conf b/conf/fail2ban/filter.d/dovecotimap.conf
index 64b8d944..40fa87a4 100644
--- a/conf/fail2ban/filter.d/dovecotimap.conf
+++ b/conf/fail2ban/filter.d/dovecotimap.conf
@@ -1,4 +1,4 @@
-# Fail2Ban filter Dovecot authentication and pop3/imap server
+# Fail2Ban filter Dovecot authentication and pop3/imap/managesieve server
 # For Mail-in-a-Box
 
 [INCLUDES]
@@ -9,7 +9,7 @@ before = common.conf
 
 _daemon = (auth|dovecot(-auth)?|auth-worker)
 
-failregex = ^%(__prefix_line)s(pop3|imap)-login: (Info: )?(Aborted login|Disconnected)(: Inactivity)? \(((no auth attempts|auth failed, \d+ attempts)( in \d+ secs)?|tried to use (disabled|disallowed) \S+ auth)\):( user=<\S*>,)?( method=\S+,)? rip=<HOST>, lip=(\d{1,3}\.){3}\d{1,3}(, TLS( handshaking)?(: Disconnected)?)?(, session=<\S+>)?\s*$
+failregex = ^%(__prefix_line)s(pop3|imap|managesieve)-login: (Info: )?(Aborted login|Disconnected)(: Inactivity)? \(((no auth attempts|auth failed, \d+ attempts)( in \d+ secs)?|tried to use (disabled|disallowed) \S+ auth)\):( user=<\S*>,)?( method=\S+,)? rip=<HOST>, lip=(\d{1,3}\.){3}\d{1,3}(, TLS( handshaking)?(: Disconnected)?)?(, session=<\S+>)?\s*$
 
 ignoreregex =
 
diff --git a/management/backup.py b/management/backup.py
index 93136bf5..11cdbb8a 100755
--- a/management/backup.py
+++ b/management/backup.py
@@ -15,8 +15,8 @@ from exclusiveprocess import Lock
 from utils import load_environment, shell, wait_for_service, fix_boto
 
 rsync_ssh_options = [
-	"--ssh-options='-i /root/.ssh/id_rsa_miab'",
-	"--rsync-options=-e \"/usr/bin/ssh -oStrictHostKeyChecking=no -oBatchMode=yes -p 22 -i /root/.ssh/id_rsa_miab\"",
+	"--ssh-options= -i /root/.ssh/id_rsa_miab",
+	"--rsync-options= -e \"/usr/bin/ssh -oStrictHostKeyChecking=no -oBatchMode=yes -p 22 -i /root/.ssh/id_rsa_miab\"",
 ]
 
 def backup_status(env):
@@ -406,7 +406,7 @@ def list_target_files(config):
 				reason = "Provided path {} is invalid.".format(target_path)
 			elif 'Network is unreachable' in listing:
 				reason = "The IP address {} is unreachable.".format(target.hostname)
-			elif 'Could not resolve hostname':
+			elif 'Could not resolve hostname' in listing:
 				reason = "The hostname {} cannot be resolved.".format(target.hostname)
 			else:
 				reason = "Unknown error." \
diff --git a/management/dns_update.py b/management/dns_update.py
index 7e006d0b..dba6dbc1 100755
--- a/management/dns_update.py
+++ b/management/dns_update.py
@@ -903,10 +903,14 @@ def set_secondary_dns(hostnames, env):
 			else:
 				# Validate IP address.
 				try:
-					v = ipaddress.ip_address(item[4:]) # raises a ValueError if there's a problem
-					if not isinstance(v, ipaddress.IPv4Address): raise ValueError("That's an IPv6 address.")
+					if "/" in item[4:]:
+						v = ipaddress.ip_network(item[4:]) # raises a ValueError if there's a problem
+						if not isinstance(v, ipaddress.IPv4Network): raise ValueError("That's an IPv6 subnet.")
+					else:
+						v = ipaddress.ip_address(item[4:]) # raises a ValueError if there's a problem
+						if not isinstance(v, ipaddress.IPv4Address): raise ValueError("That's an IPv6 address.")
 				except ValueError:
-					raise ValueError("'%s' is not an IPv4 address." % item[4:])
+					raise ValueError("'%s' is not an IPv4 address or subnet." % item[4:])
 
 		# Set.
 		set_custom_dns_record("_secondary_nameserver", "A", " ".join(hostnames), "set", env)
diff --git a/management/status_checks.py b/management/status_checks.py
index a172b256..0accebb5 100755
--- a/management/status_checks.py
+++ b/management/status_checks.py
@@ -486,10 +486,12 @@ def check_dns_zone(domain, env, output, dns_zonefiles):
 	if custom_secondary_ns and not probably_external_dns:
 		for ns in custom_secondary_ns:
 			# We must first resolve the nameserver to an IP address so we can query it.
-			ns_ip = query_dns(ns, "A")
-			if not ns_ip:
+			ns_ips = query_dns(ns, "A")
+			if not ns_ips:
 				output.print_error("Secondary nameserver %s is not valid (it doesn't resolve to an IP address)." % ns)
 				continue
+			# Choose the first IP if nameserver returns multiple
+			ns_ip = ns_ips.split('; ')[0]
 
 			# Now query it to see what it says about this domain.
 			ip = query_dns(domain, "A", at=ns_ip, nxdomain=None)
diff --git a/management/templates/custom-dns.html b/management/templates/custom-dns.html
index c838d32a..56facdc9 100644
--- a/management/templates/custom-dns.html
+++ b/management/templates/custom-dns.html
@@ -90,7 +90,7 @@
     <div class="col-sm-offset-1 col-sm-11">
       <p class="small">
         Multiple secondary servers can be separated with commas or spaces (i.e., <code>ns2.hostingcompany.com ns3.hostingcompany.com</code>). 
-        To enable zone transfers to additional servers without listing them as secondary nameservers, add <code>xfr:IPADDRESS</code>.
+        To enable zone transfers to additional servers without listing them as secondary nameservers, add an IP address or subnet using <code>xfr:10.20.30.40</code> or <code>xfr:10.20.30.40/24</code>.
       </p>
       <p id="secondarydns-clear-instructions" style="display: none" class="small">
         Clear the input field above and click Update to use this machine itself as secondary DNS, which is the default/normal setup.
diff --git a/setup/bootstrap.sh b/setup/bootstrap.sh
index 9922c6b8..3d020225 100644
--- a/setup/bootstrap.sh
+++ b/setup/bootstrap.sh
@@ -20,7 +20,7 @@ if [ -z "$TAG" ]; then
 	# want to display in status checks.
 	if [ "`lsb_release -d | sed 's/.*:\s*//' | sed 's/18\.04\.[0-9]/18.04/' `" == "Ubuntu 18.04 LTS" ]; then
 		# This machine is running Ubuntu 18.04.
-		TAG=v0.42b-quota-0.18-beta
+		TAG=v0.43-quota-0.18-beta
 
 	elif [ "`lsb_release -d | sed 's/.*:\s*//' | sed 's/14\.04\.[0-9]/14.04/' `" == "Ubuntu 14.04 LTS" ]; then
 		# This machine is running Ubuntu 14.04.
diff --git a/setup/mail-postfix.sh b/setup/mail-postfix.sh
index c71818dd..684aafdd 100755
--- a/setup/mail-postfix.sh
+++ b/setup/mail-postfix.sh
@@ -208,7 +208,34 @@ tools/editconf.py /etc/postfix/main.cf \
 # e-mails really latter, delay of greylisting has been set to
 # 180 seconds (default is 300 seconds).
 tools/editconf.py /etc/default/postgrey \
-	POSTGREY_OPTS=\"'--inet=127.0.0.1:10023 --delay=180'\"
+	POSTGREY_OPTS=\"'--inet=127.0.0.1:10023 --delay=180 --whitelist-recipients=/etc/postgrey/whitelist_clients'\"
+
+
+# We are going to setup a newer whitelist for postgrey, the version included in the distribution is old
+cat > /etc/cron.daily/mailinabox-postgrey-whitelist << EOF;
+#!/bin/bash
+
+# Mail-in-a-Box
+
+# check we have a postgrey_whitelist_clients file and that it is not older than 28 days
+if [ ! -f /etc/postgrey/whitelist_clients ] || find /etc/postgrey/whitelist_clients -mtime +28 > /dev/null ; then
+    # ok we need to update the file, so lets try to fetch it
+    if curl https://postgrey.schweikert.ch/pub/postgrey_whitelist_clients --output /tmp/postgrey_whitelist_clients -sS --fail > /dev/null 2>&1 ; then
+        # if fetching hasn't failed yet then check it is a plain text file
+        # curl manual states that --fail sometimes still produces output
+        # this final check will at least check the output is not html
+        # before moving it into place
+        if [ "\$(file -b --mime-type /tmp/postgrey_whitelist_clients)" == "text/plain" ]; then
+            mv /tmp/postgrey_whitelist_clients /etc/postgrey/whitelist_clients
+            service postgrey restart
+	else
+            rm /tmp/postgrey_whitelist_clients
+        fi
+    fi
+fi
+EOF
+chmod +x /etc/cron.daily/mailinabox-postgrey-whitelist
+/etc/cron.daily/mailinabox-postgrey-whitelist
 
 # Increase the message size limit from 10MB to 128MB.
 # The same limit is specified in nginx.conf for mail submitted via webmail and Z-Push.
diff --git a/setup/nextcloud.sh b/setup/nextcloud.sh
index 9f36ee56..d5a8e7c5 100755
--- a/setup/nextcloud.sh
+++ b/setup/nextcloud.sh
@@ -25,12 +25,12 @@ InstallNextcloud() {
 	echo "Upgrading to Nextcloud version $version"
 	echo
 
+        # Download and verify
+        wget_verify https://download.nextcloud.com/server/releases/nextcloud-$version.zip $hash /tmp/nextcloud.zip
+
 	# Remove the current owncloud/Nextcloud
 	rm -rf /usr/local/lib/owncloud
 
-	# Download and verify
-	wget_verify https://download.nextcloud.com/server/releases/nextcloud-$version.zip $hash /tmp/nextcloud.zip
-
 	# Extract ownCloud/Nextcloud
 	unzip -q /tmp/nextcloud.zip -d /usr/local/lib
 	mv /usr/local/lib/nextcloud /usr/local/lib/owncloud
@@ -90,11 +90,26 @@ InstallNextcloud() {
 	fi
 }
 
+# Nextcloud Version to install. Checks are done down below to step through intermediate versions.
 nextcloud_ver=15.0.8
 nextcloud_hash=4129d8d4021c435f2e86876225fb7f15adf764a3
-# Check if Nextcloud dir exist, and check if version matches nextcloud_ver (if either doesn't - install/upgrade)
-if [ ! -d /usr/local/lib/owncloud/ ] \
-		|| ! grep -q $nextcloud_ver /usr/local/lib/owncloud/version.php; then
+
+# Current Nextcloud Version, #1623
+# Checking /usr/local/lib/owncloud/version.php shows version of the Nextcloud application, not the DB
+# $STORAGE_ROOT/owncloud is kept together even during a backup.  It is better to rely on config.php than
+# version.php since the restore procedure can leave the system in a state where you have a newer Nextcloud
+# application version than the database.
+
+# If config.php exists, get version number, otherwise CURRENT_NEXTCLOUD_VER is empty.
+if [ -f "$STORAGE_ROOT/owncloud/config.php" ]; then
+	CURRENT_NEXTCLOUD_VER=$(php -r "include(\"$STORAGE_ROOT/owncloud/config.php\"); echo(\$CONFIG['version']);")
+else
+	CURRENT_NEXTCLOUD_VER=""
+fi
+
+# If the Nextcloud directory is missing (never been installed before, or the nextcloud version to be installed is different
+# from the version currently installed, do the install/upgrade
+if [ ! -d /usr/local/lib/owncloud/ ] || [[ ! ${CURRENT_NEXTCLOUD_VER} =~ ^$nextcloud_ver ]]; then
 
 	# Stop php-fpm if running. If theyre not running (which happens on a previously failed install), dont bail.
 	service php7.2-fpm stop &> /dev/null || /bin/true
@@ -115,25 +130,21 @@ if [ ! -d /usr/local/lib/owncloud/ ] \
 	fi
 
 	# If ownCloud or Nextcloud was previously installed....
-	if [ -e /usr/local/lib/owncloud/version.php ]; then
+	if [ ! -z ${CURRENT_NEXTCLOUD_VER} ]; then
 		# Database migrations from ownCloud are no longer possible because ownCloud cannot be run under
 		# PHP 7.
-		if grep -q "OC_VersionString = '[89]\." /usr/local/lib/owncloud/version.php; then
+		if [[ ${CURRENT_NEXTCLOUD_VER} =~ ^[89] ]]; then
 			echo "Upgrades from Mail-in-a-Box prior to v0.28 (dated July 30, 2018) with Nextcloud < 13.0.6 (you have ownCloud 8 or 9) are not supported. Upgrade to Mail-in-a-Box version v0.30 first. Setup aborting."
 			exit 1
-		fi
-		if grep -q "OC_VersionString = '1[012]\." /usr/local/lib/owncloud/version.php; then
+		elif [[ ${CURRENT_NEXTCLOUD_VER} =~ ^1[012] ]]; then
 			echo "Upgrades from Mail-in-a-Box prior to v0.28 (dated July 30, 2018) with Nextcloud < 13.0.6 (you have ownCloud 10, 11 or 12) are not supported. Upgrade to Mail-in-a-Box version v0.30 first. Setup aborting."
 			exit 1
-		fi
-		# If we are running Nextcloud 13, upgrade to Nextcloud 14
-		if grep -q "OC_VersionString = '13\." /usr/local/lib/owncloud/version.php; then
+		elif [[ ${CURRENT_NEXTCLOUD_VER} =~ ^13 ]]; then
+			# If we are running Nextcloud 13, upgrade to Nextcloud 14
 			InstallNextcloud 14.0.6 4e43a57340f04c2da306c8eea98e30040399ae5a
-
-		fi
-		# During the upgrade from Nextcloud 14 to 15, user_external may cause the upgrade to fail.
-		# We will disable it here before the upgrade and install it again after the upgrade.
-		if grep -q "OC_VersionString = '14\." /usr/local/lib/owncloud/version.php; then
+		elif [[ ${CURRENT_NEXTCLOUD_VER} =~ ^14 ]]; then
+			# During the upgrade from Nextcloud 14 to 15, user_external may cause the upgrade to fail.
+			# We will disable it here before the upgrade and install it again after the upgrade.
 			hide_output sudo -u www-data php /usr/local/lib/owncloud/console.php app:disable user_external
 		fi
 	fi
diff --git a/setup/webmail.sh b/setup/webmail.sh
index e6d1925c..5e1c6233 100755
--- a/setup/webmail.sh
+++ b/setup/webmail.sh
@@ -28,8 +28,8 @@ apt_install \
 # Install Roundcube from source if it is not already present or if it is out of date.
 # Combine the Roundcube version number with the commit hash of plugins to track
 # whether we have the latest version of everything.
-VERSION=1.3.9
-HASH=02850972b416bbfa1c13580f16d06fd7ae2774aa
+VERSION=1.3.10
+HASH=431625fc737e301f9b7e502cccc61e50a24786b8
 PERSISTENT_LOGIN_VERSION=dc5ca3d3f4415cc41edb2fde533c8a8628a94c76
 HTML5_NOTIFIER_VERSION=4b370e3cd60dabd2f428a26f45b677ad1b7118d5
 CARDDAV_VERSION=3.0.3
diff --git a/tests/fail2ban.py b/tests/fail2ban.py
index 0a3c1da4..1cb55eba 100644
--- a/tests/fail2ban.py
+++ b/tests/fail2ban.py
@@ -90,6 +90,26 @@ def pop_test():
 		if M:
 			M.quit()
 
+def managesieve_test():
+	# We don't have a Python sieve client, so we'll
+	# just run the IMAP client and see what happens.
+	import imaplib
+
+	try:
+		M = imaplib.IMAP4(hostname, 4190)
+	except ConnectionRefusedError:
+		# looks like fail2ban worked
+		raise IsBlocked()
+
+	try:
+		M.login("fakeuser", "fakepassword")
+		raise Exception("authentication didn't fail")
+	except imaplib.IMAP4.error:
+		# authentication should fail
+		pass
+	finally:
+		M.logout() # shuts down connection, has nothing to do with login()
+
 def http_test(url, expected_status, postdata=None, qsargs=None, auth=None):
 	import urllib.parse
 	import requests
@@ -208,6 +228,9 @@ if __name__ == "__main__":
 	# POP
 	run_test(pop_test, [], 20, 30, 4)
 
+	# Managesieve
+	run_test(managesieve_test, [], 20, 30, 4)
+
 	# Mail-in-a-Box control panel
 	run_test(http_test, ["/admin/me", 200], 20, 30, 1)