bpo-43218: Prevent venv creation when the target directory contains a PATH separator. (GH-24530)

2 files changed, 11 insertions, 0 deletions

diff --git a/Lib/test/test_venv.py b/Lib/test/test_venv.py
index c91b754..d96cf1e 100644
--- a/Lib/test/test_venv.py
+++ b/Lib/test/test_venv.py
@@ -467,6 +467,14 @@ class BasicTest(BaseTest):
             'import os; print("__PYVENV_LAUNCHER__" in os.environ)'])
         self.assertEqual(out.strip(), 'False'.encode())
 
+    def test_pathsep_error(self):
+        """
+        Test that venv creation fails when the target directory contains
+        the path separator.
+        """
+        rmtree(self.env_dir)
+        self.assertRaises(ValueError, venv.create, self.env_dir + os.pathsep)
+
 @requireVenvCreate
 class EnsurePipTest(BaseTest):
     """Test venv module installation of pip."""
diff --git a/Lib/venv/__init__.py b/Lib/venv/__init__.py
index a8640d9..7bfbadd 100644
--- a/Lib/venv/__init__.py
+++ b/Lib/venv/__init__.py
@@ -116,6 +116,9 @@ class EnvBuilder:
             elif os.path.islink(d) or os.path.isfile(d):
                 raise ValueError('Unable to create directory %r' % d)
 
+        if os.pathsep in env_dir:
+            raise ValueError(f'Refusing to create a venv in {env_dir} because '
+                             f'it contains the PATH separator {os.pathsep}.')
         if os.path.exists(env_dir) and self.clear:
             self.clear_directory(env_dir)
         context = types.SimpleNamespace()