Description
A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.
Published: 2021-05-27
Score: 9.1 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-2388-1 nss security update
Debian DLA Debian DLA DLA-3327-1 nss security update
EUVD EUVD EUVD-2020-4715 A flaw was found in the way CHACHA20-POLY1305 was implemented in NSS in versions before 3.55. When using multi-part Chacha20, it could cause out-of-bounds reads. This issue was fixed by explicitly disabling multi-part ChaCha20 (which was not functioning correctly) and strictly enforcing tag length. The highest threat from this vulnerability is to confidentiality and system availability.
Ubuntu USN Ubuntu USN USN-4476-1 NSS vulnerability
History

Sun, 13 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00192}

epss

{'score': 0.00191}


Subscriptions

Mozilla Nss
Redhat Enterprise Linux Openshift Do Rhel Aus Rhel E4s Rhel Eus Rhel Tus
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2024-08-04T11:56:51.720Z

Reserved: 2020-04-28T00:00:00.000Z

Link: CVE-2020-12403

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-05-27T19:15:07.953

Modified: 2024-11-21T04:59:38.987

Link: CVE-2020-12403

cve-icon Redhat

Severity : Moderate

Publid Date: 2020-07-27T00:00:00Z

Links: CVE-2020-12403 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses