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From 82dbaffa36fe317e331b2d22c5efbb6a0b6c7b19 Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Tue, 8 Oct 2024 09:15:09 +0200
Subject: [PATCH] Prevent command injection

---
 docs/changelog/2768.bugfix.rst                |  2 ++
 src/virtualenv/activation/bash/activate.sh    |  9 +++++----
 src/virtualenv/activation/batch/__init__.py   |  4 ++++
 src/virtualenv/activation/cshell/activate.csh | 10 +++++-----
 src/virtualenv/activation/fish/activate.fish  |  8 ++++----
 src/virtualenv/activation/nushell/__init__.py | 19 ++++++++++++++++++
 src/virtualenv/activation/nushell/activate.nu |  8 ++++----
 .../activation/powershell/__init__.py         | 12 +++++++++++
 .../activation/powershell/activate.ps1        |  6 +++---
 src/virtualenv/activation/python/__init__.py  |  6 +++++-
 .../activation/python/activate_this.py        |  6 +++---
 src/virtualenv/activation/via_template.py     | 15 ++++++++++++--
 tests/conftest.py                             |  6 +++++-
 tests/unit/activation/conftest.py             |  3 +--
 tests/unit/activation/test_batch.py           | 10 +++++-----
 tests/unit/activation/test_powershell.py      | 20 ++++++++++++++-----
 16 files changed, 105 insertions(+), 39 deletions(-)
 create mode 100644 docs/changelog/2768.bugfix.rst

diff --git a/docs/changelog/2768.bugfix.rst b/docs/changelog/2768.bugfix.rst
new file mode 100644
index 0000000..7651eb6
--- /dev/null
+++ b/docs/changelog/2768.bugfix.rst
@@ -0,0 +1,2 @@
+Properly quote string placeholders in activation script templates to mitigate
+potential command injection - by :user:`y5c4l3`.
diff --git a/src/virtualenv/activation/bash/activate.sh b/src/virtualenv/activation/bash/activate.sh
index fb40db6..d047ea4 100644
--- a/src/virtualenv/activation/bash/activate.sh
+++ b/src/virtualenv/activation/bash/activate.sh
@@ -44,14 +44,14 @@ deactivate () {
 # unset irrelevant variables
 deactivate nondestructive
 
-VIRTUAL_ENV='__VIRTUAL_ENV__'
+VIRTUAL_ENV=__VIRTUAL_ENV__
 if ([ "$OSTYPE" = "cygwin" ] || [ "$OSTYPE" = "msys" ]) && $(command -v cygpath &> /dev/null) ; then
     VIRTUAL_ENV=$(cygpath -u "$VIRTUAL_ENV")
 fi
 export VIRTUAL_ENV
 
 _OLD_VIRTUAL_PATH="$PATH"
-PATH="$VIRTUAL_ENV/__BIN_NAME__:$PATH"
+PATH="$VIRTUAL_ENV/"__BIN_NAME__":$PATH"
 export PATH
 
 # unset PYTHONHOME if set
@@ -62,8 +62,9 @@ fi
 
 if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT-}" ] ; then
     _OLD_VIRTUAL_PS1="${PS1-}"
-    if [ "x__VIRTUAL_PROMPT__" != x ] ; then
-        PS1="(__VIRTUAL_PROMPT__) ${PS1-}"
+    if [ "x"__VIRTUAL_PROMPT__ != x ] ; then
+        PROMPT=__VIRTUAL_PROMPT__
+        PS1="(${PROMPT}) ${PS1-}"
     else
         PS1="(`basename \"$VIRTUAL_ENV\"`) ${PS1-}"
     fi
diff --git a/src/virtualenv/activation/batch/__init__.py b/src/virtualenv/activation/batch/__init__.py
index 13ba097..b3e8540 100644
--- a/src/virtualenv/activation/batch/__init__.py
+++ b/src/virtualenv/activation/batch/__init__.py
@@ -13,6 +13,10 @@ class BatchActivator(ViaTemplateActivator):
         yield "deactivate.bat"
         yield "pydoc.bat"
 
+    @staticmethod
+    def quote(string):
+        return string
+
     def instantiate_template(self, replacements, template, creator):
         # ensure the text has all newlines as \r\n - required by batch
         base = super().instantiate_template(replacements, template, creator)
diff --git a/src/virtualenv/activation/cshell/activate.csh b/src/virtualenv/activation/cshell/activate.csh
index 837dcda..fcec426 100644
--- a/src/virtualenv/activation/cshell/activate.csh
+++ b/src/virtualenv/activation/cshell/activate.csh
@@ -10,15 +10,15 @@ alias deactivate 'test $?_OLD_VIRTUAL_PATH != 0 && setenv PATH "$_OLD_VIRTUAL_PA
 # Unset irrelevant variables.
 deactivate nondestructive
 
-setenv VIRTUAL_ENV '__VIRTUAL_ENV__'
+setenv VIRTUAL_ENV __VIRTUAL_ENV__
 
 set _OLD_VIRTUAL_PATH="$PATH:q"
-setenv PATH "$VIRTUAL_ENV:q/__BIN_NAME__:$PATH:q"
+setenv PATH "$VIRTUAL_ENV:q/"__BIN_NAME__":$PATH:q"
 
 
 
-if ('__VIRTUAL_PROMPT__' != "") then
-    set env_name = '(__VIRTUAL_PROMPT__) '
+if (__VIRTUAL_PROMPT__ != "") then
+    set env_name = __VIRTUAL_PROMPT__
 else
     set env_name = '('"$VIRTUAL_ENV:t:q"') '
 endif
@@ -42,7 +42,7 @@ if ( $do_prompt == "1" ) then
         if ( "$prompt:q" =~ *"$newline:q"* ) then
             :
         else
-            set prompt = "$env_name:q$prompt:q"
+            set prompt = '('"$env_name:q"') '"$prompt:q"
         endif
     endif
 endif
diff --git a/src/virtualenv/activation/fish/activate.fish b/src/virtualenv/activation/fish/activate.fish
index 62f631e..3637d55 100644
--- a/src/virtualenv/activation/fish/activate.fish
+++ b/src/virtualenv/activation/fish/activate.fish
@@ -57,7 +57,7 @@ end
 # Unset irrelevant variables.
 deactivate nondestructive
 
-set -gx VIRTUAL_ENV '__VIRTUAL_ENV__'
+set -gx VIRTUAL_ENV __VIRTUAL_ENV__
 
 # https://github.com/fish-shell/fish-shell/issues/436 altered PATH handling
 if test (echo $FISH_VERSION | head -c 1) -lt 3
@@ -65,7 +65,7 @@ if test (echo $FISH_VERSION | head -c 1) -lt 3
 else
     set -gx _OLD_VIRTUAL_PATH $PATH
 end
-set -gx PATH "$VIRTUAL_ENV"'/__BIN_NAME__' $PATH
+set -gx PATH "$VIRTUAL_ENV"'/'__BIN_NAME__ $PATH
 
 # Unset `$PYTHONHOME` if set.
 if set -q PYTHONHOME
@@ -87,8 +87,8 @@ if test -z "$VIRTUAL_ENV_DISABLE_PROMPT"
 
         # Prompt override provided?
         # If not, just prepend the environment name.
-        if test -n '__VIRTUAL_PROMPT__'
-            printf '(%s) ' '__VIRTUAL_PROMPT__'
+        if test -n __VIRTUAL_PROMPT__
+            printf '(%s) ' __VIRTUAL_PROMPT__
         else
             printf '(%s) ' (basename "$VIRTUAL_ENV")
         end
diff --git a/src/virtualenv/activation/nushell/__init__.py b/src/virtualenv/activation/nushell/__init__.py
index 4e2ea77..c96af22 100644
--- a/src/virtualenv/activation/nushell/__init__.py
+++ b/src/virtualenv/activation/nushell/__init__.py
@@ -5,6 +5,25 @@ class NushellActivator(ViaTemplateActivator):
     def templates(self):
         yield "activate.nu"
 
+    @staticmethod
+    def quote(string):
+        """
+        Nushell supports raw strings like: r###'this is a string'###.
+
+        This method finds the maximum continuous sharps in the string and then
+        quote it with an extra sharp.
+        """
+        max_sharps = 0
+        current_sharps = 0
+        for char in string:
+            if char == "#":
+                current_sharps += 1
+                max_sharps = max(current_sharps, max_sharps)
+            else:
+                current_sharps = 0
+        wrapping = "#" * (max_sharps + 1)
+        return f"r{wrapping}'{string}'{wrapping}"
+
     def replacements(self, creator, dest_folder):  # noqa: U100
         return {
             "__VIRTUAL_PROMPT__": "" if self.flag_prompt is None else self.flag_prompt,
diff --git a/src/virtualenv/activation/nushell/activate.nu b/src/virtualenv/activation/nushell/activate.nu
index 3da1519..569a8a1 100644
--- a/src/virtualenv/activation/nushell/activate.nu
+++ b/src/virtualenv/activation/nushell/activate.nu
@@ -31,8 +31,8 @@ export-env {
     }
 
     let is_windows = ($nu.os-info.name | str downcase) == 'windows'
-    let virtual_env = '__VIRTUAL_ENV__'
-    let bin = '__BIN_NAME__'
+    let virtual_env = __VIRTUAL_ENV__
+    let bin = __BIN_NAME__
     let path_sep = (char esep)
     let path_name = (if $is_windows {
         if (has-env 'Path') {
@@ -73,10 +73,10 @@ export-env {
       $new_env
     } else {
       # Creating the new prompt for the session
-      let virtual_prompt = (if ('__VIRTUAL_PROMPT__' == '') {
+      let virtual_prompt = (if (__VIRTUAL_PROMPT__ == '') {
           $'(char lparen)($virtual_env | path basename)(char rparen) '
       } else {
-          '(__VIRTUAL_PROMPT__) '
+          (__VIRTUAL_PROMPT__)
       })
 
       # Back up the old prompt builder
diff --git a/src/virtualenv/activation/powershell/__init__.py b/src/virtualenv/activation/powershell/__init__.py
index 4e74ecb..773d690 100644
--- a/src/virtualenv/activation/powershell/__init__.py
+++ b/src/virtualenv/activation/powershell/__init__.py
@@ -5,6 +5,18 @@ class PowerShellActivator(ViaTemplateActivator):
     def templates(self):
         yield "activate.ps1"
 
+    @staticmethod
+    def quote(string):
+        """
+        This should satisfy PowerShell quoting rules [1], unless the quoted
+        string is passed directly to Windows native commands [2].
+
+        [1]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_quoting_rules
+        [2]: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_parsing#passing-arguments-that-contain-quote-characters
+        """  # noqa: D205
+        string = string.replace("'", "''")
+        return f"'{string}'"
+
 
 __all__ = [
     "PowerShellActivator",
diff --git a/src/virtualenv/activation/powershell/activate.ps1 b/src/virtualenv/activation/powershell/activate.ps1
index d524347..346980d 100644
--- a/src/virtualenv/activation/powershell/activate.ps1
+++ b/src/virtualenv/activation/powershell/activate.ps1
@@ -35,18 +35,18 @@ $env:VIRTUAL_ENV = $VIRTUAL_ENV
 
 New-Variable -Scope global -Name _OLD_VIRTUAL_PATH -Value $env:PATH
 
-$env:PATH = "$env:VIRTUAL_ENV/__BIN_NAME____PATH_SEP__" + $env:PATH
+$env:PATH = "$env:VIRTUAL_ENV/" + __BIN_NAME__ + __PATH_SEP__ + $env:PATH
 if (!$env:VIRTUAL_ENV_DISABLE_PROMPT) {
     function global:_old_virtual_prompt {
         ""
     }
     $function:_old_virtual_prompt = $function:prompt
 
-    if ("__VIRTUAL_PROMPT__" -ne "") {
+    if (__VIRTUAL_PROMPT__ -ne "") {
         function global:prompt {
             # Add the custom prefix to the existing prompt
             $previous_prompt_value = & $function:_old_virtual_prompt
-            ("(__VIRTUAL_PROMPT__) " + $previous_prompt_value)
+            ((__VIRTUAL_PROMPT__) + $previous_prompt_value)
         }
     }
     else {
diff --git a/src/virtualenv/activation/python/__init__.py b/src/virtualenv/activation/python/__init__.py
index a49444b..8f0971e 100644
--- a/src/virtualenv/activation/python/__init__.py
+++ b/src/virtualenv/activation/python/__init__.py
@@ -9,10 +9,14 @@ class PythonActivator(ViaTemplateActivator):
     def templates(self):
         yield "activate_this.py"
 
+    @staticmethod
+    def quote(string):
+        return repr(string)
+
     def replacements(self, creator, dest_folder):
         replacements = super().replacements(creator, dest_folder)
         lib_folders = OrderedDict((os.path.relpath(str(i), str(dest_folder)), None) for i in creator.libs)
-        lib_folders = os.pathsep.join(lib_folders.keys()).replace("\\", "\\\\")  # escape Windows path characters
+        lib_folders = os.pathsep.join(lib_folders.keys())
         win_py2 = creator.interpreter.platform == "win32" and creator.interpreter.version_info.major == 2
         replacements.update(
             {
diff --git a/src/virtualenv/activation/python/activate_this.py b/src/virtualenv/activation/python/activate_this.py
index e8eeb84..976952e 100644
--- a/src/virtualenv/activation/python/activate_this.py
+++ b/src/virtualenv/activation/python/activate_this.py
@@ -14,7 +14,7 @@ except NameError:
     raise AssertionError("You must use exec(open(this_file).read(), {'__file__': this_file}))")
 
 bin_dir = os.path.dirname(abs_file)
-base = bin_dir[: -len("__BIN_NAME__") - 1]  # strip away the bin part from the __file__, plus the path separator
+base = bin_dir[: -len(__BIN_NAME__) - 1]  # strip away the bin part from the __file__, plus the path separator
 
 # prepend bin to PATH (this file is inside the bin directory)
 os.environ["PATH"] = os.pathsep.join([bin_dir] + os.environ.get("PATH", "").split(os.pathsep))
@@ -22,9 +22,9 @@ os.environ["VIRTUAL_ENV"] = base  # virtual env is right above bin directory
 
 # add the virtual environments libraries to the host python import mechanism
 prev_length = len(sys.path)
-for lib in "__LIB_FOLDERS__".split(os.pathsep):
+for lib in __LIB_FOLDERS__.split(os.pathsep):
     path = os.path.realpath(os.path.join(bin_dir, lib))
-    site.addsitedir(path.decode("utf-8") if "__DECODE_PATH__" else path)
+    site.addsitedir(path.decode("utf-8") if __DECODE_PATH__ else path)
 sys.path[:] = sys.path[prev_length:] + sys.path[0:prev_length]
 
 sys.real_prefix = sys.prefix
diff --git a/src/virtualenv/activation/via_template.py b/src/virtualenv/activation/via_template.py
index cc9dbda..b1dfa6b 100644
--- a/src/virtualenv/activation/via_template.py
+++ b/src/virtualenv/activation/via_template.py
@@ -1,4 +1,5 @@
 import os
+import shlex
 import sys
 from abc import ABCMeta, abstractmethod
 
@@ -19,6 +20,16 @@ class ViaTemplateActivator(Activator, metaclass=ABCMeta):
     def templates(self):
         raise NotImplementedError
 
+    @staticmethod
+    def quote(string):
+        """
+        Quote strings in the activation script.
+
+        :param string: the string to quote
+        :return: quoted string that works in the activation script
+        """
+        return shlex.quote(string)
+
     def generate(self, creator):
         dest_folder = creator.bin_dir
         replacements = self.replacements(creator, dest_folder)
@@ -58,8 +69,8 @@ class ViaTemplateActivator(Activator, metaclass=ABCMeta):
         binary = read_binary(self.__module__, template)
         text = binary.decode("utf-8", errors="strict")
         for key, value in replacements.items():
-            value = self._repr_unicode(creator, value)
-            text = text.replace(key, value)
+            value_uni = self._repr_unicode(creator, value)
+            text = text.replace(key, self.quote(value_uni))
         return text
 
     @staticmethod
diff --git a/tests/conftest.py b/tests/conftest.py
index a7ec4e0..b2fae66 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -292,7 +292,11 @@ def is_inside_ci():
 
 @pytest.fixture(scope="session")
 def special_char_name():
-    base = "e-$ Γ¨Ρ€Ρ‚πŸš’β™žδΈ­η‰‡-j"
+    base = "'\";&&e-$ Γ¨Ρ€Ρ‚πŸš’β™žδΈ­η‰‡-j"
+    if IS_WIN:
+        # get rid of invalid characters on Windows
+        base = base.replace('"', "")
+        base = base.replace(";", "")
     # workaround for pypy3 https://bitbucket.org/pypy/pypy/issues/3147/venv-non-ascii-support-windows
     encoding = "ascii" if IS_WIN else sys.getfilesystemencoding()
     # let's not include characters that the file system cannot encode)
diff --git a/tests/unit/activation/conftest.py b/tests/unit/activation/conftest.py
index e24a4fc..2d8b3ce 100644
--- a/tests/unit/activation/conftest.py
+++ b/tests/unit/activation/conftest.py
@@ -4,7 +4,6 @@ import subprocess
 import sys
 from os.path import dirname, normcase
 from pathlib import Path
-from shlex import quote
 from subprocess import Popen
 
 import pytest
@@ -146,7 +145,7 @@ class ActivationTester:
         assert out[-1] == "None", raw
 
     def quote(self, s):
-        return quote(s)
+        return self.of_class.quote(s)
 
     def python_cmd(self, cmd):
         return f"{os.path.basename(sys.executable)} -c {self.quote(cmd)}"
diff --git a/tests/unit/activation/test_batch.py b/tests/unit/activation/test_batch.py
index 9e6d6d6..e95f7ea 100644
--- a/tests/unit/activation/test_batch.py
+++ b/tests/unit/activation/test_batch.py
@@ -1,5 +1,3 @@
-from shlex import quote
-
 import pytest
 
 from virtualenv.activation import BatchActivator
@@ -25,10 +23,12 @@ def test_batch(activation_tester_class, activation_tester, tmp_path):
             return ["@echo off", "", "chcp 65001 1>NUL"] + super()._get_test_lines(activate_script)
 
         def quote(self, s):
-            """double quotes needs to be single, and single need to be double"""
-            return "".join(("'" if c == '"' else ('"' if c == "'" else c)) for c in quote(s))
+            if '"' in s or " " in s:
+                text = s.replace('"', r"\"")
+                return f'"{text}"'
+            return s
 
         def print_prompt(self):
-            return "echo %PROMPT%"
+            return 'echo "%PROMPT%"'
 
     activation_tester(Batch)
diff --git a/tests/unit/activation/test_powershell.py b/tests/unit/activation/test_powershell.py
index 761237f..f495353 100644
--- a/tests/unit/activation/test_powershell.py
+++ b/tests/unit/activation/test_powershell.py
@@ -1,5 +1,4 @@
 import sys
-from shlex import quote
 
 import pytest
 
@@ -19,10 +18,6 @@ def test_powershell(activation_tester_class, activation_tester, monkeypatch):
             self.activate_cmd = "."
             self.script_encoding = "utf-16"
 
-        def quote(self, s):
-            """powershell double quote needed for quotes within single quotes"""
-            return quote(s).replace('"', '""')
-
         def _get_test_lines(self, activate_script):
             # for BATCH utf-8 support need change the character code page to 650001
             return super()._get_test_lines(activate_script)
@@ -33,4 +28,19 @@ def test_powershell(activation_tester_class, activation_tester, monkeypatch):
         def print_prompt(self):
             return "prompt"
 
+        def quote(self, s):
+            """
+            Tester will pass strings to native commands on Windows so extra
+            parsing rules are used. Check `PowerShellActivator.quote` for more
+            details.
+            """
+            text = PowerShellActivator.quote(s)
+            return text.replace('"', '""') if sys.platform == "win32" else text
+
+        def activate_call(self, script):
+            # Commands are called without quotes in PowerShell
+            cmd = self.activate_cmd
+            scr = self.quote(str(script))
+            return f"{cmd} {scr}".strip()
+
     activation_tester(PowerShell)
-- 
2.46.2