diff --git a/src/base/preferences.cpp b/src/base/preferences.cpp
index 7742ac281..b76198e93 100644
--- a/src/base/preferences.cpp
+++ b/src/base/preferences.cpp
@@ -548,10 +548,9 @@ QVector<Utils::Net::Subnet> Preferences::getWebUiAuthSubnetWhitelist() const
 
     for (const QString &rawSubnet : subnets)
     {
-        bool ok = false;
-        const Utils::Net::Subnet subnet = Utils::Net::parseSubnet(rawSubnet.trimmed(), &ok);
-        if (ok)
-            ret.append(subnet);
+        const std::optional<Utils::Net::Subnet> subnet = Utils::Net::parseSubnet(rawSubnet.trimmed());
+        if (subnet)
+            ret.append(subnet.value());
     }
 
     return ret;
@@ -561,9 +560,7 @@ void Preferences::setWebUiAuthSubnetWhitelist(QStringList subnets)
 {
     Algorithm::removeIf(subnets, [](const QString &subnet)
     {
-        bool ok = false;
-        Utils::Net::parseSubnet(subnet.trimmed(), &ok);
-        return !ok;
+        return !Utils::Net::parseSubnet(subnet.trimmed()).has_value();
     });
 
     setValue(u"Preferences/WebUI/AuthSubnetWhitelist"_qs, subnets);
diff --git a/src/base/utils/net.cpp b/src/base/utils/net.cpp
index aab83656c..4a8e5690f 100644
--- a/src/base/utils/net.cpp
+++ b/src/base/utils/net.cpp
@@ -47,22 +47,15 @@ namespace Utils
             return !QHostAddress(ip).isNull();
         }
 
-        Subnet parseSubnet(const QString &subnetStr, bool *ok)
+        std::optional<Subnet> parseSubnet(const QString &subnetStr)
         {
-            const Subnet invalid = qMakePair(QHostAddress(), -1);
             const Subnet subnet = QHostAddress::parseSubnet(subnetStr);
-            if (ok)
-                *ok = (subnet != invalid);
+            const Subnet invalid = {QHostAddress(), -1};
+            if (subnet == invalid)
+                return std::nullopt;
             return subnet;
         }
 
-        bool canParseSubnet(const QString &subnetStr)
-        {
-            bool ok = false;
-            parseSubnet(subnetStr, &ok);
-            return ok;
-        }
-
         bool isLoopbackAddress(const QHostAddress &addr)
         {
             return (addr == QHostAddress::LocalHost)
@@ -70,7 +63,7 @@ namespace Utils
                     || (addr == QHostAddress(u"::ffff:127.0.0.1"_qs));
         }
 
-        bool isIPInRange(const QHostAddress &addr, const QVector<Subnet> &subnets)
+        bool isIPInSubnets(const QHostAddress &addr, const QVector<Subnet> &subnets)
         {
             QHostAddress protocolEquivalentAddress;
             bool addrConversionOk = false;
diff --git a/src/base/utils/net.h b/src/base/utils/net.h
index f9712d59c..f3c5d8ddd 100644
--- a/src/base/utils/net.h
+++ b/src/base/utils/net.h
@@ -28,8 +28,10 @@
 
 #pragma once
 
-#include <QHostAddress>
+#include <optional>
+
 #include <QtContainerFwd>
+#include <QHostAddress>
 
 class QSslCertificate;
 class QSslKey;
@@ -37,13 +39,13 @@ class QString;
 
 namespace Utils::Net
 {
+    // alias for `QHostAddress::parseSubnet()` return type
     using Subnet = QPair<QHostAddress, int>;
 
     bool isValidIP(const QString &ip);
-    Subnet parseSubnet(const QString &subnetStr, bool *ok = nullptr);
-    bool canParseSubnet(const QString &subnetStr);
+    std::optional<Subnet> parseSubnet(const QString &subnetStr);
     bool isLoopbackAddress(const QHostAddress &addr);
-    bool isIPInRange(const QHostAddress &addr, const QVector<Subnet> &subnets);
+    bool isIPInSubnets(const QHostAddress &addr, const QVector<Subnet> &subnets);
     QString subnetToString(const Subnet &subnet);
     QHostAddress canonicalIPv6Addr(const QHostAddress &addr);
 
diff --git a/src/gui/ipsubnetwhitelistoptionsdialog.cpp b/src/gui/ipsubnetwhitelistoptionsdialog.cpp
index 96da8fcbc..3a0e92a2f 100644
--- a/src/gui/ipsubnetwhitelistoptionsdialog.cpp
+++ b/src/gui/ipsubnetwhitelistoptionsdialog.cpp
@@ -90,16 +90,15 @@ void IPSubnetWhitelistOptionsDialog::on_buttonBox_accepted()
 
 void IPSubnetWhitelistOptionsDialog::on_buttonWhitelistIPSubnet_clicked()
 {
-    bool ok = false;
-    const Utils::Net::Subnet subnet = Utils::Net::parseSubnet(m_ui->txtIPSubnet->text(), &ok);
-    if (!ok)
+    const std::optional<Utils::Net::Subnet> subnet = Utils::Net::parseSubnet(m_ui->txtIPSubnet->text());
+    if (!subnet)
     {
         QMessageBox::critical(this, tr("Error"), tr("The entered subnet is invalid."));
         return;
     }
 
     m_model->insertRow(m_model->rowCount());
-    m_model->setData(m_model->index(m_model->rowCount() - 1, 0), Utils::Net::subnetToString(subnet));
+    m_model->setData(m_model->index(m_model->rowCount() - 1, 0), Utils::Net::subnetToString(subnet.value()));
     m_ui->txtIPSubnet->clear();
     m_modified = true;
 }
@@ -114,5 +113,5 @@ void IPSubnetWhitelistOptionsDialog::on_buttonDeleteIPSubnet_clicked()
 
 void IPSubnetWhitelistOptionsDialog::on_txtIPSubnet_textChanged(const QString &subnetStr)
 {
-    m_ui->buttonWhitelistIPSubnet->setEnabled(Utils::Net::canParseSubnet(subnetStr));
+    m_ui->buttonWhitelistIPSubnet->setEnabled(Utils::Net::parseSubnet(subnetStr).has_value());
 }
diff --git a/src/gui/optionsdialog.ui b/src/gui/optionsdialog.ui
index 35b7664a5..284107c85 100644
--- a/src/gui/optionsdialog.ui
+++ b/src/gui/optionsdialog.ui
@@ -3397,7 +3397,7 @@ Use ';' to split multiple entries. Can use wildcard '*'.</string>
                     <item>
                      <widget class="QLineEdit" name="textTrustedReverseProxiesList">
                       <property name="toolTip">
-                       <string>Specify reverse proxy IPs in order to use forwarded client address (X-Forwarded-For attribute), use ';' to split multiple entries.</string>
+                       <string>Specify reverse proxy IPs (or subnets, e.g. 0.0.0.0/24) in order to use forwarded client address (X-Forwarded-For header). Use ';' to split multiple entries.</string>
                       </property>
                      </widget>
                     </item>
diff --git a/src/webui/webapplication.cpp b/src/webui/webapplication.cpp
index 179db7108..d35a48c87 100644
--- a/src/webui/webapplication.cpp
+++ b/src/webui/webapplication.cpp
@@ -42,7 +42,6 @@
 #include <QUrl>
 
 #include "base/algorithm.h"
-#include "base/global.h"
 #include "base/http/httperror.h"
 #include "base/logger.h"
 #include "base/preferences.h"
@@ -402,15 +401,29 @@ void WebApplication::configure()
     m_isReverseProxySupportEnabled = pref->isWebUIReverseProxySupportEnabled();
     if (m_isReverseProxySupportEnabled)
     {
-        m_trustedReverseProxyList.clear();
-
         const QStringList proxyList = pref->getWebUITrustedReverseProxiesList().split(u';', Qt::SkipEmptyParts);
 
-        for (const QString &proxy : proxyList)
+        m_trustedReverseProxyList.clear();
+        m_trustedReverseProxyList.reserve(proxyList.size());
+
+        for (QString proxy : proxyList)
         {
-            QHostAddress ip;
-            if (ip.setAddress(proxy))
-                m_trustedReverseProxyList.push_back(ip);
+            if (!proxy.contains(u'/'))
+            {
+                const QAbstractSocket::NetworkLayerProtocol protocol = QHostAddress(proxy).protocol();
+                if (protocol == QAbstractSocket::IPv4Protocol)
+                {
+                    proxy.append(u"/32");
+                }
+                else if (protocol == QAbstractSocket::IPv6Protocol)
+                {
+                    proxy.append(u"/128");
+                }
+            }
+
+            const std::optional<Utils::Net::Subnet> subnet = Utils::Net::parseSubnet(proxy);
+            if (subnet)
+                m_trustedReverseProxyList.push_back(subnet.value());
         }
 
         if (m_trustedReverseProxyList.isEmpty())
@@ -579,7 +592,7 @@ bool WebApplication::isAuthNeeded()
 {
     if (!m_isLocalAuthEnabled && Utils::Net::isLoopbackAddress(m_clientAddress))
         return false;
-    if (m_isAuthSubnetWhitelistEnabled && Utils::Net::isIPInRange(m_clientAddress, m_authSubnetWhitelist))
+    if (m_isAuthSubnetWhitelistEnabled && Utils::Net::isIPInSubnets(m_clientAddress, m_authSubnetWhitelist))
         return false;
     return true;
 }
@@ -728,7 +741,7 @@ QHostAddress WebApplication::resolveClientAddress() const
         return m_env.clientAddress;
 
     // Only reverse proxy can overwrite client address
-    if (!m_trustedReverseProxyList.contains(m_env.clientAddress))
+    if (!Utils::Net::isIPInSubnets(m_env.clientAddress, m_trustedReverseProxyList))
         return m_env.clientAddress;
 
     const QString forwardedFor = m_request.headers.value(Http::HEADER_X_FORWARDED_FOR);
diff --git a/src/webui/webapplication.h b/src/webui/webapplication.h
index 02a8d576b..f5b0034fd 100644
--- a/src/webui/webapplication.h
+++ b/src/webui/webapplication.h
@@ -34,11 +34,13 @@
 #include <QDateTime>
 #include <QElapsedTimer>
 #include <QHash>
+#include <QHostAddress>
 #include <QMap>
 #include <QObject>
 #include <QRegularExpression>
 #include <QSet>
 #include <QTranslator>
+#include <QVector>
 
 #include "base/applicationcomponent.h"
 #include "base/global.h"
@@ -233,7 +235,7 @@ private:
 
     // Reverse proxy
     bool m_isReverseProxySupportEnabled;
-    QVector<QHostAddress> m_trustedReverseProxyList;
+    QVector<Utils::Net::Subnet> m_trustedReverseProxyList;
     QHostAddress m_clientAddress;
 
     QVector<Http::Header> m_prebuiltHeaders;
diff --git a/src/webui/www/private/views/preferences.html b/src/webui/www/private/views/preferences.html
index 4f3939849..7328dc972 100644
--- a/src/webui/www/private/views/preferences.html
+++ b/src/webui/www/private/views/preferences.html
@@ -847,7 +847,11 @@
                             <label for="webui_domain_textarea">QBT_TR(Server domains:)QBT_TR[CONTEXT=OptionsDialog]</label>
                         </td>
                         <td>
-                            <textarea id="webui_domain_textarea" rows="1" cols="60"></textarea>
+                            <textarea id="webui_domain_textarea" rows="1" cols="60" title="QBT_TR(Whitelist for filtering HTTP Host header values.
+In order to defend against DNS rebinding attack,
+you should put in domain names used by WebUI server.
+
+Use ';' to split multiple entries. Can use wildcard '*'.)QBT_TR[CONTEXT=OptionsDialog]"></textarea>
                         </td>
                     </tr>
                 </table>
@@ -869,7 +873,7 @@
             </legend>
             <div class="formRow">
                 <label for="webUIReverseProxiesListTextarea">QBT_TR(Trusted proxies list:)QBT_TR[CONTEXT=OptionsDialog]</label>
-                <input type="text" id="webUIReverseProxiesListTextarea" />
+                <input type="text" id="webUIReverseProxiesListTextarea" title="QBT_TR(Specify reverse proxy IPs (or subnets, e.g. 0.0.0.0/24) in order to use forwarded client address (X-Forwarded-For header). Use ';' to split multiple entries.)QBT_TR[CONTEXT=OptionsDialog]" />
             </div>
         </fieldset>