An out-of-bounds read flaw was found in the way Expat processed certain input. A remote attacker could send specially crafted XML that, when parsed by an application using the Expat library, would cause that application to crash or, possibly, execute arbitrary code with the permission of the user running the application.

An issue was discovered in Python through 2.7.16, 3.x through 3.5.7, 3.6.x through 3.6.9, and 3.7.x through 3.7.4. The email module wrongly parses email addresses that contain multiple @ characters. An application that uses the email module and implements some kind of checks on the From/To headers of a message could be tricked into accepting an email address that should be denied. An attack may be the same as in CVE-2019-11340; however, this CVE applies to Python more generally.

Buffer overflow in the socket.recvfrominto function in Modules/socketmodule.c in Python 2.5 before 2.7.7, 3.x before 3.3.4, and 3.4.x before 3.4rc1 allows remote attackers to execute arbitrary code via a crafted string.

libexpat. Multiple issues were addressed by updating to version 2.2.1

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.

Last updated 15 January 2025

It was found that Python's SSL hostname matching rules did not conform to RFC 6125 when the hostname included wildcards.

Upstream issue:

https://bugs.python.org/issue17997#msg194950

CVE assignment:

http://seclists.org/oss-sec/2015/q2/523

Upstream patch:

https://hg.python.org/cpython/rev/10d0edadbcdd

Array index error in the scanstring function in the json module in Python 2.7 through 3.5 and simplejson before 2.6.1 allows context-dependent attackers to read arbitrary process memory via a negative index value in the idx argument to the rawdecode function.

Alex Gaynor reports:

""" When Python's standard library HTTP clients (httplib, urllib, urllib2, xmlrpclib) are used to access resources with HTTPS, by default the certificate is not checked against any trust store, nor is the hostname in the certificate checked against the requested host. It was possible to configure a trust root to be checked against, however there were no faculties for hostname checking.

This made MITM attacks against the HTTP clients trivial, and violated RFC 2818 (http://tools.ietf.org/html/rfc2818#section-3).

Python 2.7.9 has been issued to resolve this issue. It is also resolved in 3.4.3, which has not yet been released. """

CVE request: http://seclists.org/oss-sec/2014/q4/1022

CVE-2018-20852 http.cookiejar.DefaultPolicy.domainreturnok in Lib/http/cookiejar.py in Python before 3.7.3 does not correctly validate the domain: it can be tricked into sending existing cookies to the wrong server. An attacker may abuse this flaw by using a server with a hostname that has another valid hostname as a suffix (e.g., pythonicexample.com to steal cookies for example.com). When a program uses http.cookiejar.DefaultPolicy and tries to do an HTTP connection to an attacker-controlled server, existing cookies can be leaked to the attacker. This affects 2.x through 2.7.16, 3.x before 3.4.10, 3.5.x before 3.5.7, 3.6.x before 3.6.9, and 3.7.x before 3.7.3. CVE-2014-4616 Array index error in the scanstring function in the json module in Python 2.7 through 3.5 and simplejson before 2.6.1 allows context-dependent attackers to read arbitrary process memory via a negative index value in the idx argument to the rawdecode function. CVE-2013-7040 Python 2.7 before 3.4 only uses the last eight bits of the prefix to randomize hash values, which causes it to compute hash values without restricting the ability to trigger hash collisions predictably and makes it easier for context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-1150.