CVE-2021-3426
Description
A flaw was found in Python 3's pydoc. This flaw allows a local or adjacent attacker who discovers or can convince another local or adjacent user to start a pydoc server to access the server and then use it to disclose sensitive information belonging to the other user that they would not normally have the ability to access. The highest threat from this vulnerability is to data confidentiality.
Statement
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. For more information about Red Hat Enterprise Linux support scope, please see https://access.redhat.com/support/policy/updates/errata/ .
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.7 | 5.7 | 5.7 |
| Attack Vector | Adjacent Network | Adjacent Network | Adjacent Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | None | None | None |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Acknowledgements
Red Hat would like to thank David Schwörer (Fedora) for reporting this issue.
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