Vulnerability · Published Nov 3, 2021 · Assigned by mozilla

CVE-2021-38501

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 64% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.0%top 35.6% 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 92 and Firefox ESR 91.1. 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 < 93, Thunderbird < 91.2, and Firefox ESR < 91.2.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20firefox93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.21firefox93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.22firefox93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.23firefox93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.20firefox-esr91.2.0-r0ALPINE-CVE-2021-38501
Alpine:v3.21firefox-esr91.2.0-r0ALPINE-CVE-2021-38501
Alpine:v3.22firefox-esr91.2.0-r0ALPINE-CVE-2021-38501
Alpine:v3.23firefox-esr91.2.0-r0ALPINE-CVE-2021-38501
Alpine:v3.21librewolf93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.22librewolf93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.23librewolf93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.24librewolf93.0-r0ALPINE-CVE-2021-38501
Alpine:v3.20thunderbird91.3.2-r0ALPINE-CVE-2021-38501
Alpine:v3.21thunderbird91.3.2-r0ALPINE-CVE-2021-38501
Alpine:v3.22thunderbird91.3.2-r0ALPINE-CVE-2021-38501
Alpine:v3.23thunderbird91.3.2-r0ALPINE-CVE-2021-38501
Rocky Linux:8firefox0:91.2.0-4.el8_4RLSA-2021:3755
Rocky Linux:8thunderbird0:91.2.0-1.el8_4RLSA-2021:3838
Ubuntu:22.04:LTSmozjs78no fix listedUBUNTU-CVE-2021-38501
Ubuntu:22.04:LTSthunderbird1:91.3.0+build2-0ubuntu1UBUNTU-CVE-2021-38501

Affected products (as reported)

VendorProductVersions
Mozilla Firefox unspecified – before 93
Mozilla Thunderbird unspecified – before 91.2
Mozilla Firefox ESR unspecified – before 91.2

References