Vulnerability Monitor

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CVE-2021-23336


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.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.9, indicating it can be exploited remotely over the network but requires specific conditions to be met though user interaction is required and does not require pre-existing privileges . The vulnerability impacts limited integrity, and availability (service disruption) for affected systems. Impacting 12 products from python, from fedoraproject, from debian and 9 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-02-15T13:15:12.433

Last Modified

2025-12-17T22:15:55.923

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.9 (MEDIUM)

CVSSv2 Vector

AV:N/AC:H/Au:N/C:N/I:P/A:P

  • Access Vector: NETWORK
  • Access Complexity: HIGH
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: PARTIAL
  • Availability Impact: PARTIAL
Exploitability Score

4.9

Impact Score

4.9

Weaknesses
  • Type: Primary
    CWE-444
  • Type: Secondary
    CWE-444

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application python python < 3.6.13 Yes
Application python python < 3.7.10 Yes
Application python python < 3.8.8 Yes
Application python python < 3.9.2 Yes
Operating System fedoraproject fedora 32 Yes
Operating System fedoraproject fedora 33 Yes
Operating System fedoraproject fedora 34 Yes
Operating System debian debian_linux 9.0 Yes
Application netapp cloud_backup - Yes
Application netapp inventory_collect_tool - Yes
Application netapp ontap_select_deploy_administration_utility - Yes
Application netapp snapcenter - Yes
Application djangoproject django < 2.2.19 Yes
Application djangoproject django < 3.0.13 Yes
Application djangoproject django < 3.1.7 Yes
Application oracle communications_offline_mediation_controller 12.0.0.3.0 Yes
Application oracle communications_pricing_design_center 12.0.0.3.0 Yes
Application oracle enterprise_manager_ops_center 12.4.0.0 Yes
Operating System oracle zfs_storage_appliance 8.8 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For python's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.