CVE-2020-12401

nss: ECDSA timing attack mitigation bypass

Severity Score

4.7

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

During ECDSA signature generation, padding applied in the nonce designed to ensure constant-time scalar multiplication was removed, resulting in variable-time execution dependent on secret data. This vulnerability affects Firefox < 80 and Firefox for Android < 80.

Durante la generación de firmas ECDSA, fue removido el relleno aplicado en el nonce diseñado para asegurar la multiplicación escalar de tiempo constante, resultando en una ejecución de tiempo variable dependiente de datos secretos. 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

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

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

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-04-28 CVE Reserved
2020-08-19 CVE Published
2023-03-08 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-203: Observable Discrepancy
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-2020-12401	2021-03-22
https://bugzilla.redhat.com/show_bug.cgi?id=1851294	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