Vulnerability · Published Nov 3, 2021 · Assigned by mozilla
CVE-2021-38493
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 1.2% (higher than 69% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.2%top 30.6% 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 91 and Firefox ESR 78.13. 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 ESR < 78.14, Thunderbird < 78.14, and Firefox < 92.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.21 | firefox | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.22 | firefox | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.23 | firefox | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.20 | firefox-esr | 91.2.0-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.21 | firefox-esr | 91.2.0-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.22 | firefox-esr | 91.2.0-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.23 | firefox-esr | 91.2.0-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.21 | librewolf | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.22 | librewolf | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.23 | librewolf | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.24 | librewolf | 92.0.1-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.20 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.21 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.22 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-38493 |
| Alpine:v3.23 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-38493 |
| Debian:12 | firefox-esr | 78.14.0esr-1 | DEBIAN-CVE-2021-38493 |
| Debian:13 | firefox-esr | 78.14.0esr-1 | DEBIAN-CVE-2021-38493 |
| Debian:14 | firefox-esr | 78.14.0esr-1 | DEBIAN-CVE-2021-38493 |
| Debian:12 | thunderbird | 1:78.14.0-1 | DEBIAN-CVE-2021-38493 |
| Debian:13 | thunderbird | 1:78.14.0-1 | DEBIAN-CVE-2021-38493 |
| Debian:14 | thunderbird | 1:78.14.0-1 | DEBIAN-CVE-2021-38493 |
| Rocky Linux:8 | firefox | 0:78.14.0-1.el8_4 | RLSA-2021:3497 |
| Rocky Linux:8 | thunderbird | 0:78.14.0-1.el8_4 | RLSA-2021:3499 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-38493 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox ESR | unspecified – before 78.14 |
| Mozilla | Thunderbird | unspecified – before 78.14 |
| Mozilla | Firefox | unspecified – before 92 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-38/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-42/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-39/ x_refsource_MISC
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1723391%2C1724101%2C1724107 x_refsource_MISC
- GLSA-202202-03 vendor-advisory, x_refsource_GENTOO
- GLSA-202208-14 vendor-advisory, x_refsource_GENTOO