The webbrowser.open() API would accept leading dashes in the URL which
could be handled as command line options for certain web browsers. New
behavior rejects leading dashes. Users are recommended to sanitize URLs
prior to passing to webbrowser.open().
When passing data to the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions in the "base64" module the characters "+/" will always be accepted, regardless of the value of "altchars" parameter, typically used to establish an "alternative base64 alphabet" such as the URL safe alphabet. This behavior matches what is recommended in earlier base64 RFCs, but newer RFCs now recommend either dropping characters outside the specified base64 alphabet or raising an error. The old behavior has the possibility of causing data integrity issues.
This behavior can only be insecure if your application uses an alternate base64 alphabet (without "+/"). If your application does not use the "altchars" parameter or the urlsafe_b64decode() function, then your application does not use an alternative base64 alphabet.
The attached patches DOES NOT make the base64-decode behavior raise an error, as this would be a change in behavior and break existing programs. Instead, the patch deprecates the behavior which will be replaced with the newly recommended behavior in a future version of Python. Users are recommended to mitigate by verifying user-controlled inputs match the base64
alphabet they are expecting or verify that their application would not be
affected if the b64decode() functions accepted "+" or "/" outside of altchars.
When building nested elements using xml.dom.minidom methods such as appendChild() that have a dependency on _clear_id_cache() the algorithm is quadratic. Availability can be impacted when building excessively nested documents.
When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
A vulnerability has been found in the CPython `venv` module and CLI where path names provided when creating a virtual environment were not quoted properly, allowing the creator to inject commands into virtual environment "activation" scripts (ie "source venv/bin/activate"). This means that attacker-controlled virtual environments are able to run commands when the virtual environment is activated. Virtual environments which are not created by an attacker or which aren't activated before being used (ie "./venv/bin/python") are not affected.
In Django 2.2 before 2.2.22, 3.1 before 3.1.10, and 3.2 before 3.2.2 (with Python 3.9.5+), URLValidator does not prohibit newlines and tabs (unless the URLField form field is used). If an application uses values with newlines in an HTTP response, header injection can occur. Django itself is unaffected because HttpResponse prohibits newlines in HTTP headers.
A sandboxing issue in Odoo Community 11.0 through 13.0 and Odoo Enterprise 11.0 through 13.0, when running with Python 3.6 or later, allows remote authenticated users to execute arbitrary code, leading to privilege escalation.
The updatePosition function in lib/xmltok_impl.c in libexpat in Expat 2.0.1, as used in Python, PyXML, w3c-libwww, and other software, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with crafted UTF-8 sequences that trigger a buffer over-read, a different vulnerability than CVE-2009-2625.
The pygresql module 3.8.1 and 4.0 for Python does not properly support the PQescapeStringConn function, which might allow remote attackers to leverage escaping issues involving multibyte character encodings.