Fix Regular Expression Denial of Service (ReDoS) vulnerability in
urllib.request.AbstractBasicAuthHandler. The ReDoS-vulnerable regex
has quadratic worst-case complexity and it allows cause a denial of
service when identifying crafted invalid RFCs. This ReDoS issue is on
the client side and needs remote attackers to control the HTTP server.
The AbstractBasicAuthHandler class of the urllib.request module uses
an inefficient regular expression which can be exploited by an
attacker to cause a denial of service. Fix the regex to prevent the
catastrophic backtracking. Vulnerability reported by Ben Caller
and Matt Schwager.
AbstractBasicAuthHandler of urllib.request now parses all
WWW-Authenticate HTTP headers and accepts multiple challenges per
header: use the realm of the first Basic challenge.
Co-Authored-By: Serhiy Storchaka <storchaka@gmail.com>
* bpo-39548: Fix handling of 'WWW-Authenticate' header for Digest authentication
- The 'qop' value in the 'WWW-Authenticate' header is optional. The
presence of 'qop' in the header should be checked before its value
is parsed with 'split'.
Signed-off-by: Stephen Balousek <stephen@balousek.net>
* bpo-39548: Fix handling of 'WWW-Authenticate' header for Digest authentication
- Add NEWS item
Signed-off-by: Stephen Balousek <stephen@balousek.net>
* Update Misc/NEWS.d/next/Library/2020-02-06-05-33-52.bpo-39548.DF4FFe.rst
Co-Authored-By: Brandt Bucher <brandtbucher@gmail.com>
Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>
* fix HTTP Digest handling in request.py
There is a bug triggered when server replies to a request with `WWW-Authenticate: Digest` where `qop="auth,auth-int"` rather than mere `qop="auth"`. Having both `auth` and `auth-int` is legitimate according to the `qop-options` rule in §3.2.1 of [[https://www.ietf.org/rfc/rfc2617.txt|RFC 2617]]:
> qop-options = "qop" "=" <"> 1#qop-value <">
> qop-value = "auth" | "auth-int" | token
> **qop-options**: [...] If present, it is a quoted string **of one or more** tokens indicating the "quality of protection" values supported by the server. The value `"auth"` indicates authentication; the value `"auth-int"` indicates authentication with integrity protection
This is description confirmed by the definition of the [//n//]`#`[//m//]//rule// extended-BNF pattern defined in §2.1 of [[https://www.ietf.org/rfc/rfc2616.txt|RFC 2616]] as 'a comma-separated list of //rule// with at least //n// and at most //m// items'.
When this reply is parsed by `get_authorization`, request.py only tests for identity with `'auth'`, failing to recognize it as one of the supported modes the server announced, and claims that `"qop 'auth,auth-int' is not supported"`.
* 📜🤖 Added by blurb_it.
* bpo-38686 review fix: remember why.
* fix trailing space in Lib/urllib/request.py
Co-Authored-By: Brandt Bucher <brandtbucher@gmail.com>
Capturing exceptions into names can lead to reference cycles though the __traceback__ attribute of the exceptions in some obscure cases that have been reported previously and fixed individually. As these variables are not used anyway, we can remove the binding to reduce the chances of creating reference cycles.
See for example GH-13135
CVE-2019-9948: Avoid file reading as disallowing the unnecessary URL
scheme in URLopener().open() and URLopener().retrieve()
of urllib.request.
Co-Authored-By: SH <push0ebp@gmail.com>
In urllib.request, suffixes in no_proxy environment variable with
leading dots could match related hostnames again (e.g. .b.c matches a.b.c).
Patch by Milan Oberkirch.
The deprecation include manual creation of SSLSocket and certfile/keyfile
(or similar) in ftplib, httplib, imaplib, smtplib, poplib and urllib.
ssl.wrap_socket() is not marked as deprecated yet.
When the body object is a file, its size is no longer determined with
fstat(), since that can report the wrong result (e.g. reading from a pipe).
Instead, determine the size using seek(), or fall back to chunked encoding
for unseekable files.
Also, change the logic for detecting text files to check for TextIOBase
inheritance, rather than inspecting the “mode” attribute, which may not
exist (e.g. BytesIO and StringIO). The Content-Length for text files is no
longer determined ahead of time, because the original logic could have been
wrong depending on the codec and newline translation settings.
Patch by Demian Brecht and Rolf Krahl, with a few tweaks by me.
Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is set, which
indicates that the script is in CGI mode.
Issue #27568 Reported and patch contributed by Rémi Rampin.
Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is set, which
indicates that the script is in CGI mode.
Issue #27568 Reported and patch contributed by Rémi Rampin.
Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is set, which
indicates that the script is in CGI mode.
Issue #27568 Reported and patch contributed by Rémi Rampin.
Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is set, which
indicates that the script is in CGI mode.
Issue #27568 Reported and patch contributed by Rémi Rampin.
Some servers send Location header fields with non-ASCII bytes, but "http.
client" requires the request target to be ASCII-encodable, otherwise a
UnicodeEncodeError is raised. Based on patch by Christian Heimes.
Python 2 does not suffer any problem because it allows non-ASCII bytes in the
HTTP request target.
Issue #26804: urllib.request will prefer lower_case proxy environment variables
over UPPER_CASE or Mixed_Case ones.
Patch contributed by Hans-Peter Jansen. Reviewed by Martin Panter and Senthil Kumaran.
Noah Kantrowitz
Yeting Li
Senthil Kumaran
Christian Heimes
Ronald Oussoren
Victor Stinner
Stephen Balousek
Serhiy Storchaka
PypeBros
Pablo Galindo
Zackery Spytz
Ashwin Ramaswami
Rémi Lapeyre
Steve Dower
Victor Stinner
Xtreak
Boštjan Mejak
Cheryl Sabella
INADA Naoki
Jon Dufresne
Senthil Kumaran
Xiang Zhang
Raymond Hettinger
Martin Panter
R David Murray
Berker Peksag