SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-12403

When using multi-part Chacha20, it could cause out-of-bounds reads.

CRITICAL 9.1EPSS 1.54%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
1.54% probability · 73th percentile
CISA KEV
Not listed
Weakness
CWE-125
Affected
mozilla/nss
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.