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Advisory severityMedium5.7Red Hat Linux

Medium [CVE-2021-3426] There's a flaw in Python 3's pydoc

This medium-severity Red Hat Linux advisory covers CVE-2021-3426 affecting Red Hat Enterprise Linux 8, Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS, Red Hat Quay 3.

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CVE-2021-3426 Source published Source updated

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CVE-2021-3426
Affected products & platforms
Red Hat LinuxRed Hat Enterprise Linux
Open source advisory

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Summary

There's a flaw in Python 3's 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.

Red Hat Quay from version 3.4 uses Python from Red Hat Enterprise Linux RPM repositories and therefore may receive an update for this issue in a future release. Earlier versions of Red Hat Quay will not receive a patch for this issue.

Python 2.x.x as shipped in any Red Hat product is not affected. This flaw is out of support scope for python3 as shipped with Red Hat Enterprise Linux 7.

Red Hat severity: Moderate — CVSS 5.7 (CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N). Weakness: CWE-200.

Affected Red Hat products: Red Hat Enterprise Linux 8; Red Hat Software Collections for Red Hat Enterprise Linux 7; Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS; Red Hat Enterprise Linux 7; Red Hat Quay 3. Will not fix / out of support: Red Hat Enterprise Linux 7; Red Hat Quay 3.

Red Hat fixing advisory: RHSA-2021:4160, RHSA-2021:4162, RHSA-2021:4399, RHSA-2021:3254.

Affected versions
  • < 3.8.9
  • < 3.9.3
  • < 3.10.0a7
  • 3.10

Official advisory · high-confidence parse· fetched 17 hours ago·verify at source

Fixed versions
  • python39:3.9-8050020210811100211.d428a79b
  • python39-devel:3.9-8050020210811100211.d428a79b
  • python38:3.8-8050020210811101222.e3d35cca
  • python38-devel:3.8-8050020210811101222.e3d35cca
  • python3-0:3.6.8-41.el8
  • rh-python38-babel-0:2.7.0-12.el7
  • rh-python38-python-0:3.8.11-2.el7
  • rh-python38-python-cryptography-0:2.8-5.el7
  • rh-python38-python-jinja2-0:2.10.3-6.el7
  • rh-python38-python-lxml-0:4.4.1-7.el7
  • rh-python38-python-pip-0:19.3.1-2.el7
  • rh-python38-python-urllib3-0:1.25.7-7.el7
  • RHSA-2021:4160
  • RHSA-2021:4162
  • RHSA-2021:4399
  • RHSA-2021:3254

Official advisory · high-confidence parse· fetched 17 hours ago·verify at source

Mitigation checklist

Recommended fix / mitigation
  • Use the console (no argument needed) or HTML file (-w argument) output to generate docs rather than the HTTP server options. Put differently, do not use the -p or -n options of pydoc.

Official advisory · high-confidence parse· fetched 17 hours ago·verify at source

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