Vulnerability · Published Aug 5, 2021 · Assigned by mozilla
CVE-2021-29976
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 31.1% 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 code shared between Firefox and Thunderbird. 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 Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.21 | firefox | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.22 | firefox | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.23 | firefox | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.20 | firefox-esr | 78.12.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.21 | firefox-esr | 78.12.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.22 | firefox-esr | 78.12.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.23 | firefox-esr | 78.12.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.21 | librewolf | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.22 | librewolf | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.23 | librewolf | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.24 | librewolf | 90.0-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.20 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.21 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.22 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-29976 |
| Alpine:v3.23 | thunderbird | 91.3.2-r0 | ALPINE-CVE-2021-29976 |
| Debian:12 | firefox-esr | 78.12.0esr-1 | DEBIAN-CVE-2021-29976 |
| Debian:13 | firefox-esr | 78.12.0esr-1 | DEBIAN-CVE-2021-29976 |
| Debian:14 | firefox-esr | 78.12.0esr-1 | DEBIAN-CVE-2021-29976 |
| Debian:12 | thunderbird | 1:78.12.0-1 | DEBIAN-CVE-2021-29976 |
| Debian:13 | thunderbird | 1:78.12.0-1 | DEBIAN-CVE-2021-29976 |
| Debian:14 | thunderbird | 1:78.12.0-1 | DEBIAN-CVE-2021-29976 |
| Rocky Linux:8 | firefox | 0:78.12.0-1.el8_4 | RLSA-2021:2743 |
| Rocky Linux:8 | thunderbird | 0:78.12.0-3.el8_4 | RLSA-2021:2883 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-29976 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Thunderbird | unspecified – before 78.12 |
| Mozilla | Firefox ESR | unspecified – before 78.12 |
| Mozilla | Firefox | unspecified – before 90 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-28/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-30/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-29/ x_refsource_MISC
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1700895%2C1703334%2C1706910%2C1711576%2C1714391 x_refsource_MISC
- GLSA-202202-03 vendor-advisory, x_refsource_GENTOO
- GLSA-202208-14 vendor-advisory, x_refsource_GENTOO