Vulnerability · Published Feb 26, 2021 · Assigned by mozilla

CVE-2021-23965

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 1.0% (higher than 62% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.0%top 38.0% 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. 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20firefox85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.21firefox85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.22firefox85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.23firefox85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.21librewolf85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.22librewolf85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.23librewolf85.0-r0ALPINE-CVE-2021-23965
Alpine:v3.24librewolf85.0-r0ALPINE-CVE-2021-23965
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2021-23965

Affected products (as reported)

VendorProductVersions
Mozilla Firefox < 85

References