Skip to content

gh-99889: Fix directory traversal security flaw in uu.decode() #104096

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
gpshead merged 6 commits into from
May 9, 2023
Merged

gh-99889: Fix directory traversal security flaw in uu.decode() #104096

Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
087561f
pythongh-99889: Fix directory traversal security flaw in uu.decode()
samcarroll42 May 2, 2023
2d2b53a
📜🤖 Added by blurb_it.
blurb-it[bot] May 2, 2023
5791bd6
also check absolute paths and os.altsep
gpshead May 9, 2023
ee09838
ReSTify the news entry.
gpshead May 9, 2023
7c29894
Merge branch 'main' into main
gpshead May 9, 2023
6bc681e
Add a regression test.
gpshead May 9, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
also check absolute paths and os.altsep
  • Loading branch information
@gpshead
gpshead authored May 9, 2023
commit 5791bd6cd32c13e5a6e33b854190b836f9e2cb36
11 changes: 8 additions & 3 deletions Lib/uu.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -133,9 +133,14 @@ def decode(in_file, out_file=None, mode=None, quiet=False):
# If the filename isn't ASCII, what's up with that?!?
out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii")
if os.path.exists(out_file):
raise Error('Cannot overwrite existing file: %s' % out_file)
if '../' in out_file:
raise Error('Writing to %s would result in directory traversal' % out_file)
raise Error(f'Cannot overwrite existing file: {out_file}')
if (out_file.startswith(os.sep) or
f'..{os.sep}' in out_file or (
os.altsep and
(out_file.startswith(os.altsep) or
f'..{os.altsep}' in out_file))
):
raise Error(f'Refusing to write to {out_file} due to directory traversal')
if mode is None:
mode = int(hdrfields[1], 8)
#
Expand Down