PSF-2020-3 [CVE-2020-14422] Hash collisions in IPv4Interface and IPv6Interface

Lib/ipaddress.py in Python through 3.8.3 improperly computes hash values in the IPv4Interface and IPv6Interface classes, which might allow a remote attacker to cause a denial of service if an application is affected by the performance of a dictionary containing IPv4Interface or IPv6Interface...

PSF-2020-1 xmlrpc gzip unlimited read

The gzipdecode function in the xmlrpc client library in Python 3.4 and earlier allows remote attackers to cause a denial of service memory consumption via a crafted HTTP request...

PSF-2020-8 urllib basic auth regex denial of service

Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service ReDoS attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking...

PSF-2020-7 CVE-2020-8315: Unsafe DLL loading in getpathp.c on Windows 7

In Python CPython 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1, an insecure dependency load upon launch on Windows 7 may result in an attacker's copy of api-ms-win-core-path-l1-1-0.dll being loaded and used instead of the system's copy. Windows 8 and later are unaffected...

PSF-2019-16 Email header injection in Address objects

It is possible to inject email headers using CR or LF character. The fix disallows CR and LF characters in email.headerregistry.Address arguments to guard against header injection attacks...

PSF-2019-15 Remove newline characters from uu encoding methods

Filenames passed to the UU encoding methods uu.py and uucodec.py that contain a newline character will overflow data into the UU content section. This can potentially be used to inject replace or corrupt data content in a file during the decode process. The fix removes newline characters from...

PSF-2019-2 HTTPoxy attack

The CGIHandler class in Python before 2.7.12 does not protect against the HTTPPROXY variable name clash in a CGI script, which could allow a remote attacker to redirect HTTP requests...

PSF-2019-14 Regular Expression Denial of Service in http.cookiejar

The regex http.cookiejar.LOOSEHTTPDATERE is vulnerable to regular expression denial of service "REDoS". LOOSEHTTPDATERE.match is called when using http.cookiejar.CookieJar to parse Set-Cookie headers returned by a HTTP server. Processing a response from a malicious HTTP server can lead to extreme...

PSF-2019-8 TALOS-2018-0758 SSL CRL distribution points Denial of Service

An exploitable denial-of-service vulnerability exists in the X509 certificate parser of Python.org Python 2.7.11 / 3.6.6. A specially crafted X509 certificate can cause a NULL pointer dereference, resulting in a denial of service. An attacker can initiate or accept TLS connections using crafted...

PSF-2019-7 CVE-2019-18348: CRLF injection via the host part of the url passed to urlopen()

An issue was discovered in urllib2 in Python 2.x through 2.7.17 and urllib in Python 3.x through 3.8.0. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n specifically in the host component of a URL follow...

PSF-2019-5 email.utils.parseaddr mistakenly parse an email

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 header...

PSF-2019-13 ssl.match_hostname() ignores extra string after whitespace in IPv4 address

inetaton accepts trailing characters after a valid IP. Because of that, Python ssl.matchhostname'1.1.1.1 ; this should not work but does' succeeded when it should fail. The issue was introduced in bpo-32819 by commit aef1283b . Only Python 3.7 and newer are affected. It's a potential security bug...

PSF-2019-4 Windows: vulnerable bzip2 1.0.6

BZ2decompress in decompress.c in bzip2 through 1.0.6 has an out-of-bounds write when there are many selectors...

PSF-2019-3 urlsplit does not handle NFKC normalization (second fix)

A security regression of CVE-2019-9636 was discovered in python since commit d537ab0ff9767ef024f26246899728f0116b1ec3 affecting versions 2.7, 3.5, 3.6, 3.7 and from v3.8.0a4 through v3.8.0b1, which still allows an attacker to exploit CVE-2019-9636 by abusing the user and password parts of a URL...

PSF-2019-12 urllib module local_file:// scheme

urllib in Python 2.x through 2.7.16 supports the localfile: scheme, which makes it easier for remote attackers to bypass protection mechanisms that blacklist file: URIs, as demonstrated by triggering a urllib.urlopen'localfile:///etc/passwd' call...

PSF-2019-11 HTTP Header Injection (follow-up of CVE-2016-5699)

An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n specifically in the path component of a URL that...

PSF-2019-10 HTTP Header Injection (follow-up of CVE-2016-5699)

An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n specifically in the query string after a ? charact...

PSF-2019-9 urlsplit does not handle NFKC normalization

Python 2.7.x through 2.7.16 and 3.x through 3.7.2 is affected by: Improper Handling of Unicode Encoding with an incorrect netloc during NFKC normalization. The impact is: Information disclosure credentials, cookies, etc. that are cached against a given hostname. The components are:...

PSF-2019-17 http.cookiejar: Incorrect validation of path

Cookies of example.com with path=/any were sent to example.com/anybad/ while using a cookiejar with http.cookiejar.DefaultCookiePolicy policy. The code did not check for the first non-matching character in prefix match to be a slash...

PSF-2018-6 pickle.load denial of service

Modules/pickle.c in Python before 3.7.1 has an integer overflow via a large LONGBINPUT value that is mishandled during a "resize to twice the size" attempt. This issue might cause memory exhaustion, but is only relevant if the pickle format is used for serializing tens or hundreds of gigabytes of...

PSF-2018-5 _elementree C accelerator doesn't call XML_SetHashSalt()

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...

PSF-2018-7 xml package does not obey ignore_environment

On two occasions, the xml package uses environment variables to override parser / DOM implementations: xml.sax package and xml.dom.domreg module. On both occasions, the code should not use env vars to override module names, when the interpreter is started with flags like -E or -I...

PSF-2018-4 difflib and poplib catastrophic backtracking

python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.ISLINEJUNK method. An attacker could use this flaw to cause denial of service...

PSF-2018-3 difflib and poplib catastrophic backtracking

python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in pop3lib's apop method. An attacker could use this flaw to cause denial of service...

PSF-2018-1 Expat 2.2.1

An integer overflow during the parsing of XML using the Expat library. This vulnerability affects Firefox 50...

PSF-2018-8 Email folding function Denial-of-Service

The email folding function enters an infinite loop if a header is longer than the policy maximum line length and contains many non-ASCII characters. Regression introduced in Python 3.6.4...

PSF-2018-2 Python 2.7 readahead is not thread safe

Python 2.7.14 is vulnerable to a Heap-Buffer-Overflow as well as a Heap-Use-After-Free. Python versions prior to 2.7.14 may also be vulnerable and it appears that Python 2.7.17 and prior may also be vulnerable however this has not been confirmed. The vulnerability lies when multiply threads are...

PSF-2017-6 PyString_DecodeEscape integer overflow

CPython aka Python up to 2.7.13 is vulnerable to an integer overflow in the PyStringDecodeEscape function in stringobject.c, resulting in heap-based buffer overflow and possible arbitrary code execution...

PSF-2017-1 JSONDecoder.raw_decode

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...

PSF-2017-7 Expat 2.2.1

XML External Entity vulnerability in libexpat 2.2.0 and earlier Expat XML Parser Library allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD...

PSF-2017-11 Expat 2.2.3

Expat 2.2.2 was released with multiple security fixes: 43: Protect against compilation without any source of high quality entropy enabled, e.g. with CMake build system 60: Windows with UNICODE: Unintended use of LoadLibraryW with a non-wide string resulted in failure to load advapi32.dll and...

PSF-2017-8 Environment variables injection in subprocess on Windows

On Windows, prevent passing invalid environment variables and command arguments to subprocess.Popen. It is possible to inject an environment variable in subprocess on Windows if a user data is passed to a subprocess via environment variable. Check for invalid environment variable names containing...

PSF-2017-9 bpo-30500: urllib connects to a wrong host

The urllib module doesn't parse correctly password containing the character...

PSF-2017-2 Zlib 1.2.11

inftrees.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic...

PSF-2017-3 Zlib 1.2.11

inffast.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic...

PSF-2017-4 Zlib 1.2.11

The inflateMark function in inflate.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving left shifts of negative integers...

PSF-2017-10 urllib FTP protocol stream injection

FTP protocol stream injection via malicious URLs...

PSF-2016-10 gettext.c2py()

Arbitrary code execution in gettext.c2py...

PSF-2016-8 HTTP header injection

CRLF injection vulnerability in the HTTPConnection.putheader function in urllib2 and urllib in CPython aka Python before 2.7.10 and 3.x before 3.4.4 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in a URL...

PSF-2016-7 zipimporter overflow

Integer overflow in the getdata 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...

PSF-2016-3 smtplib TLS stripping

The smtplib library in CPython aka Python before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 does not return an error when StartTLS fails, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block...

PSF-2016-4 Sweet32 attack (DES, 3DES)

The DES and Triple DES ciphers, as used in the TLS, SSH, and IPSec protocols and other protocols and products, have a birthday bound of approximately four billion blocks, which makes it easier for remote attackers to obtain cleartext data via a birthday attack against a long-duration encrypted...

PSF-2016-5 Windows: vulnerable bzip2 1.0.6

Use-after-free vulnerability in bzip2recover in bzip2 1.0.6 allows remote attackers to cause a denial of service crash via a crafted bzip2 file, related to block ends set to before the start of the block...

PSF-2016-6 Expat 2.2 (Expat bug #537)

The overflow protection in Expat is removed by compilers with certain optimization settings, which allows remote attackers to cause a denial of service crash or possibly execute arbitrary code via crafted XML data. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-1283 and...

PSF-2016-1 ssl.match_hostname() IDNA issue

The ssl.matchhostname function in CPython aka Python before 2.7.9 and 3.x before 3.3.3 does not properly handle wildcards in hostnames, which might allow man-in-the-middle attackers to spoof servers via a crafted certificate...

PSF-2016-2 Expat 2.2 (Expat bug #537)

Expat allows context-dependent attackers to cause a denial of service crash or possibly execute arbitrary code via a malformed input document, which triggers a buffer overflow...

PSF-2016-9 Issue #26657: HTTP server directory traversal

Fix directory traversal vulnerability with http.server and SimpleHTTPServer on Windows. Regression of Python 3.3.5. Python issue reported at 2016-03-14...

PSF-2015-1 Issue #26556: Expat 2.1.1

Multiple integer overflows in the XMLGetBuffer function in Expat through 2.1.0, as used in Google Chrome before 44.0.2403.89 and other products, allow remote attackers to cause a denial of service heap-based buffer overflow or possibly have unspecified other impact via crafted XML data, a related...

PSF-2014-7 Validate TLS certificate

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'...

PSF-2014-5 os.makedirs() not thread-safe

Race condition in the getmaskedmode function in Lib/os.py in Python 3.2 through 3.5, when existok 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...