Debian DLA-1834-1 : python2.7 security update
Medium Nessus Plugin ID 126222
SynopsisThe remote Debian host is missing a security update.
DescriptionMultiple vulnerabilities were discovered in Python, an interactive high-level object-oriented language, including
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.
NULL pointer dereference using a specially crafted X509 certificate.
Improper Handling of Unicode Encoding (with an incorrect netloc) during NFKC normalization resulting in information disclosure (credentials, cookies, etc. that are cached against a given hostname).
A specially crafted URL could be incorrectly parsed to locate cookies or authentication data and send that information to a different host than when parsed correctly.
An issue was discovered in urllib2 where 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 ? character) followed by an HTTP header or a Redis command.
An issue was discovered in urllib2 where 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 lacks a ? character) followed by an HTTP header or a Redis command. This is similar to the CVE-2019-9740 query string issue.
urllib supports the local_file: scheme, which makes it easier for remote attackers to bypass protection mechanisms that blacklist file:
URIs, as demonstrated by triggering a urllib.urlopen('local_file:///etc/passwd') call.
A security regression of CVE-2019-9636 was discovered which still allows an attacker to exploit CVE-2019-9636 by abusing the user and password parts of a URL. When an application parses user-supplied URLs to store cookies, authentication credentials, or other kind of information, it is possible for an attacker to provide specially crafted URLs to make the application locate host-related information (e.g. cookies, authentication data) and send them to a different host than where it should, unlike if the URLs had been correctly parsed.
The result of an attack may vary based on the application.
For Debian 8 'Jessie', these problems have been fixed in version 2.7.9-2+deb8u3.
We recommend that you upgrade your python2.7 packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpgrade the affected packages.