A python-werkzeug security update has been released for Debian GNU/Linux 10 LTS to address two vulnerabilities that allowed an attacker to inject cookies in certain situations and cause a denial of service (DoS).

DLA 3346-1: python-werkzeug security update

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Debian LTS Advisory DLA-3346-1 debian-lts@lists.debian.org
  https://www.debian.org/lts/security/ Sylvain Beucler
February 27, 2023   https://wiki.debian.org/LTS
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Package : python-werkzeug
Version : 0.14.1+dfsg1-4+deb10u2
CVE ID : CVE-2023-23934 CVE-2023-25577
Debian Bug : 1031370

Two vulnerabilities were discovered in Werkzeug, a collection of
utilities for WSGI (web) applications. An attacker may inject cookies
in specific situations, and cause a denial of service (DoS).

CVE-2023-23934

Werkzeug will parse the cookie `=__Host-test=bad` as
__Host-test=bad`. If a Werkzeug application is running next to a
vulnerable or malicious subdomain which sets such a cookie using a
vulnerable browser, the Werkzeug application will see the bad
cookie value but the valid cookie key. Browsers may allow
"nameless" cookies that look like `=value` instead of
`key=value`. A vulnerable browser may allow a compromised
application on an adjacent subdomain to exploit this to set a
cookie like `=__Host-test=bad` for another subdomain.

CVE-2023-25577

Werkzeug's multipart form data parser will parse an unlimited
number of parts, including file parts. Parts can be a small amount
of bytes, but each requires CPU time to parse and may use more
memory as Python data. If a request can be made to an endpoint
that accesses `request.data`, `request.form`, `request.files`, or
`request.get_data(parse_form_data=False)`, it can cause
unexpectedly high resource usage. This allows an attacker to cause
a denial of service by sending crafted multipart data to an
endpoint that will parse it.

For Debian 10 buster, these problems have been fixed in version
0.14.1+dfsg1-4+deb10u2.

We recommend that you upgrade your python-werkzeug packages.

For the detailed security status of python-werkzeug please refer to
its security tracker page at:
  https://security-tracker.debian.org/tracker/python-werkzeug

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS