python-urllib3/python3-urllib3: fix CVE-2020-7212

Optimize _encode_invalid_chars for a denial of service (CPU consumption)

CVE: CVE-2020-7212

Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Harpritkaur Bhandari <Harpritkaur.Bhandari@kpit.com>
[Add CVE: CVE-2020-7212 to the patch itself]
Signed-off-by: Armin Kuster <akuster808@gmail.com>

2 files changed, 57 insertions, 0 deletions

diff --git a/meta-python/recipes-devtools/python/python3-urllib3/CVE-2020-7212.patch b/meta-python/recipes-devtools/python/python3-urllib3/CVE-2020-7212.patch
new file mode 100644
index 000000000..df234e442
--- /dev/null
+++ b/meta-python/recipes-devtools/python/python3-urllib3/CVE-2020-7212.patch
@@ -0,0 +1,55 @@
+From aff951b7a41eb5b958b32c49eaa00da02adc9c2d Mon Sep 17 00:00:00 2001
+From: Quentin Pradet <quentin.pradet@gmail.com>
+Date: Tue, 21 Jan 2020 22:32:56 +0400
+Subject: [PATCH] Optimize _encode_invalid_chars (#1787)
+
+Co-authored-by: Seth Michael Larson <sethmichaellarson@gmail.com>
+
+Upstream-Status: Backport
+[from git://github.com/urllib3/urllib3.git commit:a2697e7c6b]
+CVE: CVE-2020-7212
+Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
+---
+ src/urllib3/util/url.py | 15 ++++++---------
+ 1 file changed, 6 insertions(+), 9 deletions(-)
+
+diff --git a/src/urllib3/util/url.py b/src/urllib3/util/url.py
+index 9675f74..e353937 100644
+--- a/src/urllib3/util/url.py
++++ b/src/urllib3/util/url.py
+@@ -216,18 +216,15 @@ def _encode_invalid_chars(component, allowed_chars, encoding="utf-8"):
+
+     component = six.ensure_text(component)
+
++    # Normalize existing percent-encoded bytes.
+     # Try to see if the component we're encoding is already percent-encoded
+     # so we can skip all '%' characters but still encode all others.
+-    percent_encodings = PERCENT_RE.findall(component)
+-
+-    # Normalize existing percent-encoded bytes.
+-    for enc in percent_encodings:
+-        if not enc.isupper():
+-            component = component.replace(enc, enc.upper())
++    component, percent_encodings = PERCENT_RE.subn(
++        lambda match: match.group(0).upper(), component
++    )
+
+     uri_bytes = component.encode("utf-8", "surrogatepass")
+-    is_percent_encoded = len(percent_encodings) == uri_bytes.count(b"%")
+-
++    is_percent_encoded = percent_encodings == uri_bytes.count(b"%")
+     encoded_component = bytearray()
+
+     for i in range(0, len(uri_bytes)):
+@@ -237,7 +234,7 @@ def _encode_invalid_chars(component, allowed_chars, encoding="utf-8"):
+         if (is_percent_encoded and byte == b"%") or (
+             byte_ord < 128 and byte.decode() in allowed_chars
+         ):
+-            encoded_component.extend(byte)
++            encoded_component += byte
+             continue
+         encoded_component.extend(b"%" + (hex(byte_ord)[2:].encode().zfill(2).upper()))
+
+--
+2.23.0
+
diff --git a/meta-python/recipes-devtools/python/python3-urllib3_1.25.7.bb b/meta-python/recipes-devtools/python/python3-urllib3_1.25.7.bb
index 34c15b6c2..8d987a1f3 100644
--- a/meta-python/recipes-devtools/python/python3-urllib3_1.25.7.bb
+++ b/meta-python/recipes-devtools/python/python3-urllib3_1.25.7.bb
@@ -8,6 +8,8 @@ SRC_URI[sha256sum] = "f3c5fd51747d450d4dcf6f923c81f78f811aab8205fda64b0aba34a4e4
 
 inherit pypi setuptools3
 
+SRC_URI += "file://CVE-2020-7212.patch"
+
 RDEPENDS_${PN} += "\
     ${PYTHON_PN}-certifi \
     ${PYTHON_PN}-cryptography \