CVE-2020-28493

Publication date 1 February 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
jinja2	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Ignored end of life
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Fixed 2.10.1-2ubuntu0.2
	18.04 LTS bionic	Fixed 2.10-1ubuntu0.18.04.1+esm1 Ubuntu Pro
	16.04 LTS xenial	Fixed 2.8-1ubuntu0.1+esm1 Ubuntu Pro
	14.04 LTS trusty	Fixed 2.7.2-2ubuntu0.1~esm2 Ubuntu Pro

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Notes

sbeattie

regular expression DoS

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
jinja2	Upstream: 15ef8f0

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	Low
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L