CVE-2020-6829

nss: Side channel attack on ECDSA signature generation

Severity Score

5.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

When performing EC scalar point multiplication, the wNAF point multiplication algorithm was used; which leaked partial information about the nonce used during signature generation. Given an electro-magnetic trace of a few signature generations, the private key could have been computed. This vulnerability affects Firefox < 80 and Firefox for Android < 80.

Cuando se lleva a cabo la multiplicación de puntos escalares EC, se usó el algoritmo de multiplicación de puntos wNAF; que filtró información parcial sobre el nonce usado durante la generación de firmas. Dado un rastro electromagnético de unas pocas generaciones de firmas, la clave privada podría haberse calculado. Esta vulnerabilidad afecta a Firefox versiones anteriores a 80 y Firefox para Android versiones anteriores a 80

A flaw was found in nss. Using the EM side-channel, it is possible to extract the position of zero and non-zero wNAF digits while nss-certutil tool performs scalar multiplication during the ECDSA signature generation, leaking partial information about the ECDSA nonce. Given a small number of ECDSA signatures, this information can be used to steal the private key. The highest threat from this vulnerability is to data confidentiality.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-01-10 CVE Reserved
2020-09-30 CVE Published
2024-08-04 CVE Updated
2024-09-01 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-327: Use of a Broken or Risky Cryptographic Algorithm

CAPEC

References (5)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2023/02/msg00021.html	Mailing List

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2020-36	2023-02-20
https://www.mozilla.org/security/advisories/mfsa2020-39	2023-02-20
https://access.redhat.com/security/cve/CVE-2020-6829	2021-03-22
https://bugzilla.redhat.com/show_bug.cgi?id=1826187	2021-03-22

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mozilla Search vendor "Mozilla"		Firefox Search vendor "Mozilla" for product "Firefox"				< 80.0 Search vendor "Mozilla" for product "Firefox" and version " < 80.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Search vendor "Mozilla" for product "Firefox"				< 80.0 Search vendor "Mozilla" for product "Firefox" and version " < 80.0"		android		Affected