pyrox.dev
1From 5a8d121a1f3ef5ad7c105ee378cc79a3eac0c7d4 Mon Sep 17 00:00:00 2001
2From: Rishi <rishi_devan@mail.com>
3Date: Wed, 15 Jul 2020 13:51:00 +0200
4Subject: [PATCH] bpo-39017: Avoid infinite loop in the tarfile module
5 (GH-21454)
6
7Avoid infinite loop when reading specially crafted TAR files using the tarfile module
8(CVE-2019-20907).
9---
10 Lib/tarfile.py | 2 ++
11
12diff --git a/Lib/tarfile.py b/Lib/tarfile.py
13index e2b60532f6..6769066cab 100755
14--- a/Lib/tarfile.py
15+++ b/Lib/tarfile.py
16@@ -1249,6 +1249,8 @@ class TarInfo(object):
17
18 length, keyword = match.groups()
19 length = int(length)
20+ if length == 0:
21+ raise InvalidHeaderError("invalid header")
22 value = buf[match.end(2) + 1:match.start(1) + length - 1]
23
24 # Normally, we could just use "utf-8" as the encoding and "strict"