CVE-2021-3733

Advisory lineage Upstream: 0 Downstream: 32
Modified
Published: 07 Mar 2022, 00:00
Last modified:03 Nov 2025, 21:45

Vulnerability Summary

Overall Risk (default)
medium
36/100
CVSS Score
6.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.63% LOW
1% probability -0.09%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

07 Mar 2022, 00:00
Published
Vulnerability first disclosed
03 Nov 2025, 21:45
Last Modified
Vulnerability information updated

Description

There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.

CVSS Metrics

  • v3.1•MEDIUM•Score: 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  • v2.0•MEDIUM•Score: 4AV:N/AC:L/Au:S/C:N/I:N/A:P

EPSS Trends

Current EPSS score: 0.63%• Percentile: 71%

Techniques & Countermeasures

  • CWE-400•Uncontrolled Resource Consumption

    The product does not properly control the allocation and maintenance of a limited resource.

Affected Systems

  • fedoraproject•extra_packages_for_enterprise_linux

    7.0

  • fedoraproject•fedora

    33 | 34 | 35 | 36

  • netapp•hci_compute_node_firmware

    na

  • netapp•management_services_for_element_software_and_netapp_hci

    na

  • netapp•ontap_select_deploy_administration_utility

    na

  • netapp•solidfire\,_enterprise_sds_\&_hci_storage_node

    na

  • python•python

    < 3.6.14 | ≥ 3.7.0, < 3.7.11 | ≥ 3.8.0, < 3.8.10 | ≥ 3.9.0, < 3.9.5 | 3.10.0

  • redhat•codeready_linux_builder

    8.0

  • redhat•codeready_linux_builder_for_ibm_z_systems

    8.0

  • redhat•codeready_linux_builder_for_power_little_endian

    8.0

  • redhat•enterprise_linux

    8.0

  • redhat•enterprise_linux_eus

    8.4

  • redhat•enterprise_linux_for_ibm_z_systems

    8.0

  • redhat•enterprise_linux_for_ibm_z_systems_eus

    8.4

  • redhat•enterprise_linux_for_power_little_endian

    8.0

  • redhat•enterprise_linux_for_power_little_endian_eus

    8.4

  • redhat•enterprise_linux_server_aus

    8.4

  • redhat•enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions

    8.4

  • redhat•enterprise_linux_server_tus

    8.4

  • redhat•enterprise_linux_server_update_services_for_sap_solutions

    8.4

References (9)