CVE-2021-3737

Publication date 31 August 2021

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop, consuming CPU time. The highest threat from this vulnerability is to system availability.

Read the notes from the security team

Status

Package Ubuntu Release Status
python3.10 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute Ignored end of life
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release
python3.4 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty
Fixed 3.4.3-1ubuntu1~14.04.7+esm11
python3.5 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial
Fixed 3.5.2-2ubuntu0~16.04.13+esm1
14.04 LTS trusty
Fixed 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1
python3.6 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Fixed 3.6.9-1~18.04ubuntu1.6
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release
python3.7 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.04 LTS focal Not in release
18.04 LTS bionic
Fixed 3.7.5-2ubuntu1~18.04.2
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release
python3.8 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.04 LTS focal
Fixed 3.8.10-0ubuntu1~20.04.2
18.04 LTS bionic
Fixed 3.8.0-3ubuntu1~18.04.2
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release
python3.9 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish
Not affected
21.04 hirsute
Fixed 3.9.5-3ubuntu0~21.04.1
20.04 LTS focal
Fixed 3.9.5-3ubuntu0~20.04.1
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored end of standard support
14.04 LTS trusty Not in release

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Notes

leosilva

impish/devel is not affected, code supposed affected was patched already.

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-5083-1
    • Python vulnerabilities
    • 16 September 2021
    • USN-5199-1
    • Python vulnerabilities
    • 17 December 2021
    • USN-5200-1
    • Python vulnerabilities
    • 17 December 2021
    • USN-5201-1
    • Python vulnerabilities
    • 17 December 2021

Other references