Use subprocess to Avoid shell injection in shutil module

Convert shutil._call_external_zip to use subprocess rather than distutlils.spawn
Subject: When shutil.make_archive falls back to te external zip problem, it use
subprocess to invoke it rather than distutils.spawn. This closes a possible shell
injection vector. distutils.spawn isn't very good at quoting command lines.

Resolve: https://bugs.python.org/issue34540

Original-Author: Benjamin Peterson <benjamin@python.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/lib-python/2.7/shutil.py b/lib-python/2.7/shutil.py
index 388906fd43..83a554de2c 100644
--- a/lib-python/2.7/shutil.py
+++ b/lib-python/2.7/shutil.py
@@ -396,17 +396,21 @@ def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
 
     return archive_name
 
-def _call_external_zip(base_dir, zip_filename, verbose=False, dry_run=False):
+def _call_external_zip(base_dir, zip_filename, verbose, dry_run, logger):
     # XXX see if we want to keep an external call here
     if verbose:
         zipoptions = "-r"
     else:
         zipoptions = "-rq"
-    from distutils.errors import DistutilsExecError
-    from distutils.spawn import spawn
+    cmd = ["zip", zipoptions, zip_filename, base_dir]
+    if logger is not None:
+        logger.info(' '.join(cmd))
+    if dry_run:
+        return
+    import subprocess
     try:
-        spawn(["zip", zipoptions, zip_filename, base_dir], dry_run=dry_run)
-    except DistutilsExecError:
+        subprocess.check_call(cmd)
+    except subprocess.CalledProcessError:
         # XXX really should distinguish between "couldn't find
         # external 'zip' command" and "zip failed".
         raise ExecError, \
@@ -440,7 +444,7 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
         zipfile = None
 
     if zipfile is None:
-        _call_external_zip(base_dir, zip_filename, verbose, dry_run)
+        _call_external_zip(base_dir, zip_filename, verbose, dry_run, logger)
     else:
         if logger is not None:
             logger.info("creating '%s' and adding '%s' to it",