CVE-2021-3426

Description

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.

How to fix CVE-2021-3426

To remediate CVE-2021-3426, upgrade the affected package to a fixed version below.

—upgrade to 3.9.4-r0 or later
—upgrade to 2.7.18 or later
—upgrade to 2.7.18 or later
—upgrade to 2.7.18 or later
—upgrade to 7.3.3+dfsg-4 or later
—upgrade to 3.9.2-1+deb11u2 or later

Is CVE-2021-3426 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (6)

from 0, < 3.9.4-r0
from 0, < 2.7.18, >= 3.6.0, < 3.6.13, >= 3.7.0, < 3.7.10, >= 3.8.0, < 3.8.8, >= 3.9.0, < 3.9.3
from 0, < 2.7.18, >= 3.6.0, < 3.6.13, >= 3.7.0, < 3.7.10, >= 3.8.0, < 3.8.8, >= 3.9.0, < 3.9.3
from 0, < 2.7.18, >= 3.6.0, < 3.6.13, >= 3.7.0, < 3.7.10, >= 3.8.0, < 3.8.8, >= 3.9.0, < 3.9.3
from 0, < 7.3.3+dfsg-4
from 0, < 3.9.2-1+deb11u2

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 3.1	MEDIUM5.7	CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N