CVE-2021-23336

Advisory lineage Upstream: 0 Downstream: 36
Modified
Published: 15 Feb 2021, 12:15
Last modified:17 Dec 2025, 21:16

Vulnerability Summary

Overall Risk (default)
medium
34/100
CVSS Score
5.9 MEDIUM
v3.1 (cve.org)
EPSS Score
0.3% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

15 Feb 2021, 12:15
Published
Vulnerability first disclosed
17 Dec 2025, 21:16
Last Modified
Vulnerability information updated

Description

The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H/E:P/RL:U/RC:C
  • v3.1•MEDIUM•Score: 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H
  • v2.0•MEDIUM•Score: 4AV:N/AC:H/Au:N/C:N/I:P/A:P

EPSS Trends

Current EPSS score: 0.30%• Percentile: 54%

Techniques & Countermeasures

  • CWE-444•Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

    The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

Affected Systems

  • debian•debian_linux

    9.0

  • djangoproject•django

    ≥ 2.2, < 2.2.19 | ≥ 3.0, < 3.0.13 | ≥ 3.1, < 3.1.7

  • fedoraproject•fedora

    32 | 33 | 34

  • netapp•cloud_backup

    na

  • netapp•inventory_collect_tool

    na

  • netapp•ontap_select_deploy_administration_utility

    na

  • netapp•snapcenter

    na

  • oracle•communications_offline_mediation_controller

    12.0.0.3.0

  • oracle•communications_pricing_design_center

    12.0.0.3.0

  • oracle•enterprise_manager_ops_center

    12.4.0.0

  • oracle•zfs_storage_appliance

    8.8

  • python•python

    < 3.6.13 | ≥ 3.7.0, < 3.7.10 | ≥ 3.8.0, < 3.8.8 | ≥ 3.9.0, < 3.9.2

References (37)