Python 3.9.x and 3.10.x through 3.10.8 on Linux allows local privilege escalation in a non-default configuration. The Python multiprocessing library, when used with the forkserver start method on Linux, allows pickles to be deserialized from any user in the same machine local network namespace, which in many system configurations means any user on the same machine. Pickles can execute arbitrary code. Thus, this allows for local user privilege escalation to the user that any forkserver process is running as. Setting multiprocessing.util.abstract_sockets_supported to False is a workaround. The forkserver start method for multiprocessing is not the default start method. This issue is Linux specific because only Linux supports abstract namespace sockets. CPython before 3.9 does not make use of Linux abstract namespace sockets by default. Support for users manually specifying an abstract namespace socket was added as a bugfix in 3.7.8 and 3.8.4, but users would need to make specific unco...

Python before 3.3.4 RC1 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a file size value larger than the size of the zip file to the (1) ZipExtFile.read, (2) ZipExtFile.read(n), (3) ZipExtFile.readlines, (4) ZipFile.extract, or (5) ZipFile.extractall function.

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 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 dep...

Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure.

** DISPUTED ** The Wave_read._read_fmt_chunk function in Lib/wave.py in Python through 3.6.4 does not ensure a nonzero channel value, which allows attackers to cause a denial of service (divide-by-zero and exception) via a crafted wav format audio file. NOTE: the vendor disputes this issue because Python applications "need to be prepared to handle a wide variety of exceptions."

Directory traversal vulnerability in the (1) extract and (2) extractall functions in the tarfile module in Python allows user-assisted remote attackers to overwrite arbitrary files via a .. (dot dot) sequence in filenames in a TAR archive, a related issue to CVE-2001-1267.

Python's elementtree C accelerator failed to initialise Expat's hash salt during initialization. This could make it easy to conduct denial of service attacks against Expat by constructing an XML document that would cause pathological hash collisions in Expat's internal data structures, consuming large amounts CPU and RAM. The vulnerability exists in Python versions 3.7.0, 3.6.0 through 3.6.6, 3.5.0 through 3.5.6, 3.4.0 through 3.4.9, 2.7.0 through 2.7.15.

The legacy email.utils.parseaddr function in Python through 3.11.4 allows attackers to trigger "RecursionError: maximum recursion depth exceeded while calling a Python object" via a crafted argument. This argument is plausibly an untrusted value from an application's input data that was supposed to contain a name and an e-mail address. NOTE: email.utils.parseaddr is categorized as a Legacy API in the documentation of the Python email package. Applications should instead use the email.parser.BytesParser or email.parser.Parser class.

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.

Python Software Foundation Python (CPython) version 2.7 contains a CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in shutil module (make_archive function) that can result in Denial of service, Information gain via injection of arbitrary files on the system or entire drive. This attack appear to be exploitable via Passage of unfiltered user input to the function. This vulnerability appears to have been fixed in after commit add531a1e55b0a739b0f42582f1c9747e5649ace.

Multiple integer overflows in audioop.c in the audioop module in Python 2.6, 2.7, 3.1, and 3.2 allow context-dependent attackers to cause a denial of service (application crash) via a large fragment, as demonstrated by a call to audioop.lin2lin with a long string in the first argument, leading to a buffer overflow. NOTE: this vulnerability exists because of an incorrect fix for CVE-2008-3143.5.

Race condition in the _get_masked_mode function in Lib/os.py in Python 3.2 through 3.5, when exist_ok is set to true and multiple threads are used, might allow local users to bypass intended file permissions by leveraging a separate application vulnerability before the umask has been set to the expected value.

Python 2.5.2 and earlier allows context-dependent attackers to execute arbitrary code via multiple vectors that cause a negative size value to be provided to the PyString_FromStringAndSize function, which allocates less memory than expected when assert() is disabled and triggers a buffer overflow.

The HTTP clients in the (1) httplib, (2) urllib, (3) urllib2, and (4) xmlrpclib libraries in CPython (aka Python) 2.x before 2.7.9 and 3.x before 3.4.3, when accessing an HTTPS URL, do not (a) check the certificate against a trust store or verify that the server hostname matches a domain name in the subject's (b) Common Name or (c) subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

Integer overflow in the get_data function in zipimport.c in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 allows remote attackers to have unspecified impact via a negative data size value, which triggers a heap-based buffer overflow.

Multiple integer overflows in Python 2.2.3 through 2.5.1, and 2.6, allow context-dependent attackers to have an unknown impact via a large integer value in the tabsize argument to the expandtabs method, as implemented by (1) the string_expandtabs function in Objects/stringobject.c and (2) the unicode_expandtabs function in Objects/unicodeobject.c. NOTE: this vulnerability reportedly exists because of an incomplete fix for CVE-2008-2315.

An XML External Entity (XXE) issue was discovered in Python through 3.9.1. The plistlib module no longer accepts entity declarations in XML plist files to avoid XML vulnerabilities.

The list_directory function in Lib/SimpleHTTPServer.py in SimpleHTTPServer in Python before 2.5.6c1, 2.6.x before 2.6.7 rc2, and 2.7.x before 2.7.2 does not place a charset parameter in the Content-Type HTTP header, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks against Internet Explorer 7 via UTF-7 encoding.

Algorithmic complexity vulnerability in the ssl.match_hostname function in Python 3.2.x, 3.3.x, and earlier, and unspecified versions of python-backports-ssl_match_hostname as used for older Python versions, allows remote attackers to cause a denial of service (CPU consumption) via multiple wildcard characters in the common name in a certificate.