CVE-2021-3580

Publication date 10 June 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

A flaw was found in the way nettle's RSA decryption functions handled specially crafted ciphertext. An attacker could use this flaw to provide a manipulated ciphertext leading to application crash and denial of service.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
nettle	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Fixed 3.7-2.1ubuntu1.1
	20.10 groovy	Fixed 3.6-2ubuntu0.2
	20.04 LTS focal	Fixed 3.5.1+really3.5.1-2ubuntu0.2
	18.04 LTS bionic	Fixed 3.4.1-0ubuntu0.18.04.1
	16.04 LTS xenial	Ignored change too intrusive
	14.04 LTS trusty	Ignored change too intrusive

Notes

mdeslaur

this fix relies on the RSA refactoring that is required to fix CVE-2018-16869, which is too intrusive to backport to older releases

Patch details

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

Package	Patch details
nettle	Upstream: 485b5e2 Upstream: 0ad0b5d

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