CVE Vulnerabilities

CVE-2021-3426

Exposure of Sensitive Information to an Unauthorized Actor

Published: May 20, 2021 | Modified: Nov 21, 2024
CVSS 3.x
5.7
MEDIUM
Source:
NVD
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS 2.x
2.7 LOW
AV:A/AC:L/Au:S/C:P/I:N/A:N
RedHat/V2
RedHat/V3
5.7 MODERATE
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Ubuntu
LOW

Theres a flaw in Python 3s pydoc. A local or adjacent attacker who discovers or is able to convince another local or adjacent user to start a pydoc server could access the server and use it to disclose sensitive information belonging to the other user that they would not normally be able to access. The highest risk of this flaw is to data confidentiality. This flaw affects Python versions before 3.8.9, Python versions before 3.9.3 and Python versions before 3.10.0a7.

Weakness

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Affected Software

Name Vendor Start Version End Version
Python Python * 2.7.18 (excluding)
Python Python 3.6.0 (including) 3.6.13 (excluding)
Python Python 3.7.0 (including) 3.7.10 (excluding)
Python Python 3.8.0 (including) 3.8.8 (excluding)
Python Python 3.9.0 (including) 3.9.3 (excluding)
Python Python 3.10.0-alpha1 (including) 3.10.0-alpha1 (including)
Python Python 3.10.0-alpha2 (including) 3.10.0-alpha2 (including)
Python Python 3.10.0-alpha3 (including) 3.10.0-alpha3 (including)
Python Python 3.10.0-alpha4 (including) 3.10.0-alpha4 (including)
Python Python 3.10.0-alpha5 (including) 3.10.0-alpha5 (including)
Python Python 3.10.0-alpha6 (including) 3.10.0-alpha6 (including)
Red Hat Enterprise Linux 8 RedHat python39:3.9-8050020210811100211.d428a79b *
Red Hat Enterprise Linux 8 RedHat python39-devel:3.9-8050020210811100211.d428a79b *
Red Hat Enterprise Linux 8 RedHat python38:3.8-8050020210811101222.e3d35cca *
Red Hat Enterprise Linux 8 RedHat python38-devel:3.8-8050020210811101222.e3d35cca *
Red Hat Enterprise Linux 8 RedHat python3-0:3.6.8-41.el8 *
Red Hat Enterprise Linux 8 RedHat python3-0:3.6.8-41.el8 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-babel-0:2.7.0-12.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-0:3.8.11-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-cryptography-0:2.8-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-jinja2-0:2.10.3-6.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-lxml-0:4.4.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-pip-0:19.3.1-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7 RedHat rh-python38-python-urllib3-0:1.25.7-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-babel-0:2.7.0-12.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-0:3.8.11-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-cryptography-0:2.8-5.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-jinja2-0:2.10.3-6.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-lxml-0:4.4.1-7.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-pip-0:19.3.1-2.el7 *
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS RedHat rh-python38-python-urllib3-0:1.25.7-7.el7 *
Python2.7 Ubuntu trusty *
Python3.10 Ubuntu upstream *
Python3.4 Ubuntu trusty *
Python3.4 Ubuntu trusty/esm *
Python3.5 Ubuntu esm-infra/xenial *
Python3.5 Ubuntu trusty *
Python3.5 Ubuntu trusty/esm *
Python3.5 Ubuntu xenial *
Python3.6 Ubuntu bionic *
Python3.7 Ubuntu bionic *
Python3.7 Ubuntu esm-apps/bionic *
Python3.7 Ubuntu trusty *
Python3.8 Ubuntu bionic *
Python3.8 Ubuntu esm-apps/bionic *
Python3.8 Ubuntu groovy *
Python3.9 Ubuntu focal *
Python3.9 Ubuntu groovy *
Python3.9 Ubuntu hirsute *
Python3.9 Ubuntu impish *
Python3.9 Ubuntu trusty *
Python3.9 Ubuntu upstream *

Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

Information exposures can occur in different ways:

It is common practice to describe any loss of confidentiality as an “information exposure,” but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

Potential Mitigations

  • Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
  • Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

References