Vulnerability · Published Feb 26, 2021 · Assigned by mozilla
CVE-2021-23978
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 1.5% (higher than 75% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.5%top 25.1% 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 85 and Firefox ESR 78.7. 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 < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.21 | firefox | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.22 | firefox | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.23 | firefox | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.20 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.21 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.22 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.23 | firefox-esr | 78.8.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.21 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.22 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.23 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.24 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.20 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.21 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.22 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23978 |
| Alpine:v3.23 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23978 |
| Debian:12 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23978 |
| Debian:13 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23978 |
| Debian:14 | firefox-esr | 78.8.0esr-1 | DEBIAN-CVE-2021-23978 |
| Debian:12 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23978 |
| Debian:13 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23978 |
| Debian:14 | thunderbird | 1:78.8.0-1 | DEBIAN-CVE-2021-23978 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-23978 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 86 |
| Mozilla | Thunderbird | < 78.8 |
| Mozilla | Firefox ESR | < 78.8 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-07/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-09/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-08/ x_refsource_MISC
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=786797%2C1682928%2C1687391%2C1687597 x_refsource_MISC
- [debian-lts-announce] 20210301 [SECURITY] [DLA 2578-1] thunderbird security update mailing-list, x_refsource_MLIST
- DSA-4866 vendor-advisory, x_refsource_DEBIAN
- GLSA-202104-10 vendor-advisory, x_refsource_GENTOO
- GLSA-202104-09 vendor-advisory, x_refsource_GENTOO