From ae21283e19c16116c3581105c14738e8b2c4e92d Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Sat, 29 Oct 2022 10:20:59 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- sysdiagnose-wifi-kml.py | 21 ++++++++++++++++++++- sysdiagnose-wifi-net.py | 24 +++++++++++++++++++++++- 2 files changed, 43 insertions(+), 2 deletions(-) diff --git a/sysdiagnose-wifi-kml.py b/sysdiagnose-wifi-kml.py index 95a59bb..917d269 100644 --- a/sysdiagnose-wifi-kml.py +++ b/sysdiagnose-wifi-kml.py @@ -57,7 +57,26 @@ # untar file first to current directory # tarfile.open currently Throws InvalidHeader error! with tarfile.open(options.inputfile, 'r:gz') as t: - t.extractall('./') + def is_within_directory(directory, target): + + abs_directory = os.path.abspath(directory) + abs_target = os.path.abspath(target) + + prefix = os.path.commonprefix([abs_directory, abs_target]) + + return prefix == abs_directory + + def safe_extract(tar, path=".", members=None, *, numeric_owner=False): + + for member in tar.getmembers(): + member_path = os.path.join(path, member.name) + if not is_within_directory(path, member_path): + raise Exception("Attempted Path Traversal in Tar File") + + tar.extractall(path, members, numeric_owner=numeric_owner) + + + safe_extract(t, "./") # does not get here due to exception ... todo diff --git a/sysdiagnose-wifi-net.py b/sysdiagnose-wifi-net.py index 94fd854..2544eb1 100644 --- a/sysdiagnose-wifi-net.py +++ b/sysdiagnose-wifi-net.py @@ -53,7 +53,29 @@ # untar file first to current directory # tarfile.open Throws InvalidHeader error! with tarfile.open(options.inputfile, 'r:gz') as t: - t.extractall('./') + + import os + + def is_within_directory(directory, target): + + abs_directory = os.path.abspath(directory) + abs_target = os.path.abspath(target) + + prefix = os.path.commonprefix([abs_directory, abs_target]) + + return prefix == abs_directory + + def safe_extract(tar, path=".", members=None, *, numeric_owner=False): + + for member in tar.getmembers(): + member_path = os.path.join(path, member.name) + if not is_within_directory(path, member_path): + raise Exception("Attempted Path Traversal in Tar File") + + tar.extractall(path, members, numeric_owner=numeric_owner) + + + safe_extract(t, "./") # does not get here due to exception ... todo # readfile = ass-ume extracted name is same as input name minus the .tgz