* bpo-37461: Fix infinite loop in parsing of specially crafted email headers.
Some crafted email header would cause the get_parameter method to run in an
infinite loop causing a DoS attack surface when parsing those headers. This
patch fixes that by making sure the DQUOTE character is handled to prevent
going into an infinite loop.
(cherry picked from commit a4a994bd3e)
Co-authored-by: Abhilash Raj <maxking@users.noreply.github.com>
ssl.match_hostname() no longer accepts IPv4 addresses with additional text
after the address and only quad-dotted notation without trailing
whitespaces. Some inet_aton() implementations ignore whitespace and all data
after whitespace, e.g. '127.0.0.1 whatever'.
Short notations like '127.1' for '127.0.0.1' were already filtered out.
The bug was initially found by Dominik Czarnota and reported by Paul Kehrer.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue37463
(cherry picked from commit 477b1b2576)
Co-authored-by: Christian Heimes <christian@python.org>
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>
Disallow control chars in http URLs in urllib.urlopen. This addresses a potential security problem for applications that do not sanity check their URLs where http request headers could be injected.
Don't send cookies of domain A without Domain attribute to domain B when domain A is a suffix match of domain B while using a cookiejar with `http.cookiejar.DefaultCookiePolicy` policy. Patch by Karthikeyan Singaravelan.
Fix a NULL pointer deref in ssl module. The cert parser did not handle CRL
distribution points with empty DP or URI correctly. A malicious or buggy
certificate can result into segfault.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue35746
The "-I" command line option (run Python in isolated mode) is now
also copied by the multiprocessing and distutils modules when
spawning child processes. Previously, only -E and -s options (enabled
by -I) were copied.
subprocess._args_from_interpreter_flags() now copies the -I flag.
The xml.sax and xml.dom.domreg modules now obey
sys.flags.ignore_environment.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue34791
The SAX parser no longer processes general external entities by default
to increase security. Before, the parser created network connections
to fetch remote files or loaded local files from the file system for DTD
and entities.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue17239
The C accelerated _elementtree module now initializes hash randomization
salt from _Py_HashSecret instead of libexpat's default CPRNG.
Signed-off-by: Christian Heimes <christian@python.org>
https://bugs.python.org/issue34623
* Fix integer overflow in os.readv(), os.writev(), os.preadv()
and os.pwritev() and in os.sendfile() with headers or trailers
arguments (on BSD-based OSes and MacOS).
* Fix sending the part of the file in os.sendfile() on MacOS.
Using the trailers argument could cause sending more bytes from
the input file than was specified.
Thanks Ned Deily for testing on 32-bit MacOS.
Harden ssl module against LibreSSL CVE-2018-8970.
X509_VERIFY_PARAM_set1_host() is called with an explicit namelen. A new test
ensures that NULL bytes are not allowed.
Signed-off-by: Christian Heimes <christian@python.org>
* Prevent low-grade poplib REDOS (CVE-2018-1060)
The regex to test a mail server's timestamp is susceptible to
catastrophic backtracking on long evil responses from the server.
Happily, the maximum length of malicious inputs is 2K thanks
to a limit introduced in the fix for CVE-2013-1752.
A 2KB evil response from the mail server would result in small slowdowns
(milliseconds vs. microseconds) accumulated over many apop calls.
This is a potential DOS vector via accumulated slowdowns.
Replace it with a similar non-vulnerable regex.
The new regex is RFC compliant.
The old regex was non-compliant in edge cases.
* Prevent difflib REDOS (CVE-2018-1061)
The default regex for IS_LINE_JUNK is susceptible to
catastrophic backtracking.
This is a potential DOS vector.
Replace it with an equivalent non-vulnerable regex.
Also introduce unit and REDOS tests for difflib.
Co-authored-by: Tim Peters <tim.peters@gmail.com>
Co-authored-by: Christian Heimes <christian@python.org>
Previously, the ssl module stored international domain names (IDNs)
as U-labels. This is problematic for a number of reasons -- for
example, it made it impossible for users to use a different version
of IDNA than the one built into Python.
After this change, we always convert to A-labels as soon as possible,
and use them for all internal processing. In particular, server_hostname
attribute is now an A-label, and on the server side there's a new
sni_callback that receives the SNI servername as an A-label rather than
a U-label.
Add basic fuzz tests for a few common builtin functions.
This is an easy place to start, and these functions are probably safe.
We'll want to add more fuzz tests later. Lets bootstrap using these.
While the fuzz tests are included in CPython and compiled / tested on a
very basic level inside CPython itself, the actual fuzzing happens as
part of oss-fuzz (https://github.com/google/oss-fuzz). The reason to
include the tests in CPython is to make sure that they're maintained
as part of the CPython project, especially when (as some eventually
will) they use internal implementation details in the test.
(This will be necessary sometimes because e.g. the fuzz test should
never enter Python's interpreter loop, whereas some APIs only expose
themselves publicly as Python functions.)
This particular set of changes is part of testing Python's builtins,
tracked internally at Google by b/37562550.
The _xxtestfuzz module that this change adds need not be shipped with binary distributions of Python.
SSLObject.version() now correctly returns None when handshake over BIO has
not been performed yet.
Signed-off-by: Christian Heimes <christian@python.org>
Add "Misc/NEWS.d" directory tree for "blurb".
CPython workflow is changing! We're going to start using "blurb"
to manage Misc/NEWS entries:
https://github.com/python/core-workflow
(This will be a big win for release managers, honest.)
This checkin simply populates the "Misc/NEWS.d" subdirectory tree
so that people can start putting their news entries in there.
No other changes (yet).
Łukasz Langa
Miss Islington (bot)
Victor Stinner
David Carlier
Victor Stinner
Krzysztof Wojcik
Gregory P. Smith
Steve Dower
Xtreak
Steve Dower
Christian Heimes
Serhiy Storchaka
Jamie Davis
Ned Deily
Devin Jeanpierre
larryhastings