Vulnerability · Published Mar 31, 2021 · Assigned by mozilla
CVE-2021-23987
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 73% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.4%top 27.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
Mozilla developers and community members reported memory safety bugs present in Firefox 86 and Firefox ESR 78.8. 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 < 78.9, Firefox < 87, and Thunderbird < 78.9.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.21 | firefox | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.22 | firefox | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.23 | firefox | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.20 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.21 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.22 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.23 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.21 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.22 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.23 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.24 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.20 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.21 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.22 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Alpine:v3.23 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23987 |
| Debian:12 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23987 |
| Debian:13 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23987 |
| Debian:14 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23987 |
| Debian:12 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23987 |
| Debian:13 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23987 |
| Debian:14 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23987 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-23987 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox ESR | unspecified – before 78.9 |
| Mozilla | Firefox | unspecified – before 87 |
| Mozilla | Thunderbird | unspecified – before 78.9 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-10/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-12/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-11/ x_refsource_MISC
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1513519%2C1683439%2C1690169%2C1690718 x_refsource_MISC