CVE-2020-12402

Publication date 19 June 2020

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

During RSA key generation, bignum implementations used a variation of the Binary Extended Euclidean Algorithm which entailed significantly input-dependent flow. This allowed an attacker able to perform electromagnetic-based side channel attacks to record traces leading to the recovery of the secret primes. *Note:* An unmodified Firefox browser does not generate RSA keys in normal operation and is not affected, but products built on top of it might. This vulnerability affects Firefox < 78.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
nss	20.04 LTS focal	Fixed 2:3.49.1-1ubuntu1.2
	19.10 eoan	Fixed 2:3.45-1ubuntu2.4
	18.04 LTS bionic	Fixed 2:3.35-2ubuntu2.9
	16.04 LTS xenial	Fixed 2:3.28.4-0ubuntu0.16.04.12
	14.04 LTS trusty	Fixed 2:3.28.4-0ubuntu0.14.04.5+esm6

Get expanded security coverage with Ubuntu Pro

Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use.

Get Ubuntu Pro 30-day free trial

Patch details

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

Package	Patch details
nss	Upstream: https://hg.mozilla.org/projects/nss/rev/699541a7793bbe9b20f1d73dc49e25c6054aa4c1

Severity score breakdown

Parameter	Value
Base score	4.4 · Medium
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	Required
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	None
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N