Merge commit from fork

User-controlled template sources were rendered with the unrestricted
jinja2.Template, allowing authenticated users to achieve remote code
execution. All rendering now goes through a single shared
RenderSandboxedTemplate() helper backed by jinja2.sandbox, which denies
unsafe attribute access (e.g. __globals__, __class__) while keeping the
intended templating features working:

- POST /api/email/preview: Body and Subject (GHSA-8q4m-52pw-hfmw)
- POST /api/email/send: Body and Subject (same sink class)
- POST /api/updateWireguardConfigurationInfo (OverridePeerSettings):
  values were rendered before validation, so the payload executed
  before __validateOverridePeerSettings could reject it
- Peer.downloadPeer(): rendered configuration file includes raw
  OverridePeerSettings values; also rendered for dashboard clients
  via GetAssignedPeers

Verified: lipsum.__globals__, __class__.__mro__, TemplateReference,
cycler/joiner/namespace escape chains all raise SecurityError; normal
templates ({{ configuration.* }}, {{ peer.* }}, filters, loops) render
unchanged.

Co-authored-by: DaanSelen <80752476+DaanSelen@users.noreply.github.com>

src/dashboard.py

@@ -9,8 +9,7 @@ from zipfile import ZipFile
 from datetime import datetime, timedelta
 
 import sqlalchemy
-from jinja2 import Template
-from flask import Flask, request, render_template, session, send_file, current_app, redirect, url_for
+from flask import Flask, request, render_template, session, send_file, current_app
 from flask_cors import CORS
 from icmplib import ping, traceroute
 from flask.json.provider import DefaultJSONProvider
@@ -20,7 +19,8 @@ from sqlalchemy import RowMapping
 
 from modules.Utilities import (
     RegexMatch, StringToBoolean, ValidateDNSAddress,
-    GenerateWireguardPublicKey, GenerateWireguardPrivateKey
+    GenerateWireguardPublicKey, GenerateWireguardPrivateKey,
+    RenderSandboxedTemplate
 )
 from packaging import version
 from modules.Email import EmailSender
@@ -1597,10 +1597,9 @@ def API_Email_Send():
             if configuration is not None:
                 fp, p = configuration.searchPeer(data.get('Peer'))
                 if fp:
-                    template = Template(body)
                     download = p.downloadPeer()
-                    body = template.render(peer=p.toJson(), configurationFile=download)
-                    subject = Template(data.get('Subject', '')).render(peer=p.toJson(), configurationFile=download)
+                    body = RenderSandboxedTemplate(body, peer=p.toJson(), configurationFile=download)
+                    subject = RenderSandboxedTemplate(data.get('Subject', ''), peer=p.toJson(), configurationFile=download)
                     if data.get('IncludeAttachment', False):
                         u = str(uuid4())
                         peerName = p.toJson().get('name', '').strip()
@@ -1629,11 +1628,10 @@ def API_Email_PreviewBody():
         return ResponseObject(False, "Peer does not exist")
 
     try:
-        template = Template(body)
         download = p.downloadPeer()
         return ResponseObject(data={
-            "Body": Template(body).render(peer=p.toJson(), configurationFile=download),
-            "Subject": Template(subject).render(peer=p.toJson(), configurationFile=download)
+            "Body": RenderSandboxedTemplate(body, peer=p.toJson(), configurationFile=download),
+            "Subject": RenderSandboxedTemplate(subject, peer=p.toJson(), configurationFile=download)
         })
     except Exception as e:
         return ResponseObject(False, message=str(e))

src/modules/Peer.py

@@ -7,12 +7,12 @@ import json
 import os, subprocess, uuid, random, re
 from datetime import timedelta
 
-import jinja2
 import sqlalchemy as db
 from .PeerJob import PeerJob
 from  flask import current_app
 from .PeerShareLink import PeerShareLink
-from .Utilities import GenerateWireguardPublicKey, CheckAddress, ValidateDNSAddress
+from .Utilities import GenerateWireguardPublicKey, CheckAddress, ValidateDNSAddress, \
+    RenderSandboxedTemplate
 
 
 class Peer:
@@ -237,7 +237,7 @@ class Peer:
                 if val is not None and ((type(val) is str and len(val) > 0) or (type(val) is int and val > 0)):
                     final["file"] += f"{key} = {val}\n"
 
-        final["file"] = jinja2.Template(final["file"]).render(configuration=self.configuration)
+        final["file"] = RenderSandboxedTemplate(final["file"], configuration=self.configuration)
 
 
         if self.configuration.Protocol == "awg":

src/modules/Utilities.py

@@ -1,6 +1,21 @@
 import re, ipaddress
 import subprocess
 import sqlalchemy
+from jinja2.sandbox import SandboxedEnvironment
+
+sandboxEnvironment = SandboxedEnvironment()
+
+def RenderSandboxedTemplate(source: str, **context) -> str:
+    """
+    Render a Jinja2 template within a sandboxed environment. Template sources built with
+    user-provided content (e.g. email body, peer configuration file) must go through this
+    function, so unsafe attribute access (such as __globals__) is denied and template
+    injection cannot escalate into arbitrary code execution.
+    @param source: Template source string, may contain user-provided content
+    @param context: Variables passed into the template
+    @return: Rendered template
+    """
+    return sandboxEnvironment.from_string(source).render(**context)
 
 def RegexMatch(regex, text) -> bool:
     """

src/modules/WireguardConfiguration.py

@@ -3,7 +3,6 @@ WireGuard Configuration
 """
 from typing import Any
 
-import jinja2
 import sqlalchemy, random, shutil, configparser, ipaddress, os, subprocess, time, re, uuid, psutil, traceback
 from zipfile import ZipFile
 from datetime import datetime, timedelta
@@ -21,7 +20,8 @@ from .Utilities import StringToBoolean, \
     ValidateDNSAddress, \
     ValidateEndpointAllowedIPs, \
     CheckAddress, \
-    CheckPeerKey
+    CheckPeerKey, \
+    RenderSandboxedTemplate
 from .WireguardConfigurationInfo import WireguardConfigurationInfo, PeerGroupsClass
 from .DashboardWebHooks import DashboardWebHooks
 
@@ -1242,7 +1242,7 @@ class WireguardConfiguration:
         elif key == "OverridePeerSettings":
             for (key, val) in value.items():
                 try:
-                    status, msg = self.__validateOverridePeerSettings(key, jinja2.Template(val).render(configuration=self.toJson()))
+                    status, msg = self.__validateOverridePeerSettings(key, RenderSandboxedTemplate(val, configuration=self.toJson()))
                     if not status:
                         return False, msg, key
                 except Exception as e: