CVE-2020-12400

nss: P-384 and P-521 implementation uses a side-channel vulnerable modular inversion function

Severity Score

4.7

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

When converting coordinates from projective to affine, the modular inversion was not performed in constant time, resulting in a possible timing-based side channel attack. This vulnerability affects Firefox < 80 and Firefox for Android < 80.

Cuando se convierten coordenadas desde una descriptiva a afín, la inversión modular no se llevó a cabo en un tiempo constante, resultando en un posible ataque de canal lateral basado en sincronización. Esta vulnerabilidad afecta a Firefox versiones anteriores a 80 y Firefox para Android versiones anteriores a 80

A side-channel flaw was found in NSS, in the way P-384 and P-521 curves are used in the generation of EDSA signatures, 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

High

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
2020-08-10 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-2020-12400	2021-03-22
https://bugzilla.redhat.com/show_bug.cgi?id=1853983	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