Vulnerability · Published Feb 26, 2021 · Assigned by mozilla

CVE-2021-23964

High 8.8

In plain English

A high-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 72% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.4%top 28.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

Mozilla developers reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20firefox85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.21firefox85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.22firefox85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.23firefox85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.20firefox-esr78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.21firefox-esr78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.22firefox-esr78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.23firefox-esr78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.21librewolf85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.22librewolf85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.23librewolf85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.24librewolf85.0-r0ALPINE-CVE-2021-23964
Alpine:v3.20thunderbird78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.21thunderbird78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.22thunderbird78.7.0-r0ALPINE-CVE-2021-23964
Alpine:v3.23thunderbird78.7.0-r0ALPINE-CVE-2021-23964
Debian:12firefox-esr78.7.0esr-1DEBIAN-CVE-2021-23964
Debian:13firefox-esr78.7.0esr-1DEBIAN-CVE-2021-23964
Debian:14firefox-esr78.7.0esr-1DEBIAN-CVE-2021-23964
Debian:12thunderbird1:78.7.0-1DEBIAN-CVE-2021-23964
Debian:13thunderbird1:78.7.0-1DEBIAN-CVE-2021-23964
Debian:14thunderbird1:78.7.0-1DEBIAN-CVE-2021-23964
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2021-23964

Affected products (as reported)

VendorProductVersions
Mozilla Firefox < 85
Mozilla Thunderbird < 78.7
Mozilla Firefox ESR < 78.7

References