CVE-2021-29976: High severity Mozilla Firefox ESR vulnerability
Mozilla developers Emil Ghitta, Tyson Smith, Valentin Gosu, Olli Pettay, and Randell Jesup reported memory safety bugs present in Firefox 89 and Firefox ESR 78.11. 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.
Other sources
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.
Mozilla developers Valentin Gosu, Randell Jesup, Emil Ghitta, Tyson Smith, and Olli Pettay reported memory safety bugs present in Firefox 89 and Firefox ESR 78.11. 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.
Mozilla developers Valentin Gosu, Randell Jesup, Emil Ghitta, Tyson Smith, and Olli Pettay reported memory safety bugs present in Thunderbird 78.11. 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.
— Mozilla
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/firefoxto a version that resolves this vulnerability.Fixed in 118.0.2-1 - Upgrade
Upgrade
debian/firefox-esrto a version that resolves this vulnerability.Fixed in 91.12.0esr-1~deb10u1Fixed in 115.3.1esr-1~deb10u1Fixed in 102.15.0esr-1~deb11u1Fixed in 115.3.1esr-1~deb11u1Fixed in 102.15.1esr-1~deb12u1Fixed in 115.3.0esr-1~deb12u1Fixed in 115.3.0esr-1 - Upgrade
Upgrade
debian/thunderbirdto a version that resolves this vulnerability.Fixed in 1:91.12.0-1~deb10u1Fixed in 1:115.3.1-1~deb10u1Fixed in 1:102.13.1-1~deb11u1Fixed in 1:115.3.1-1~deb11u1Fixed in 1:102.15.1-1~deb12u1Fixed in 1:115.3.1-1~deb12u1Fixed in 1:115.3.1-1 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 78.12 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 78.12 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 90 - Upgrade
Upgrade
alpine/firefoxto a version that resolves this vulnerability.Fixed in 90.0-r0 - Upgrade
Upgrade
alpine/firefox-esrto a version that resolves this vulnerability.Fixed in 78.12.0-r0 - Upgrade
Upgrade
alpine/librewolfto a version that resolves this vulnerability.Fixed in 90.0-r0 - Upgrade
Upgrade
alpine/mozjs78to a version that resolves this vulnerability.Fixed in 78.12.0-r0 - Upgrade
Upgrade
alpine/thunderbirdto a version that resolves this vulnerability.Fixed in 91.3.2-r0
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
Frequently Asked Questions
What is the severity of CVE-2021-29976?
CVE-2021-29976 is classified as a high-severity vulnerability due to potential memory corruption issues.
How do I fix CVE-2021-29976?
To fix CVE-2021-29976, update to Firefox version 90 or later, or Firefox ESR version 78.12 or later.
What products are affected by CVE-2021-29976?
CVE-2021-29976 affects Firefox 89, Firefox ESR 78.11, and earlier versions of these products.
Can CVE-2021-29976 be exploited?
Yes, although exploitation would require considerable effort due to memory safety issues involved.
Who reported CVE-2021-29976?
CVE-2021-29976 was reported by Mozilla developers Emil Ghitta, Tyson Smith, Valentin Gosu, Olli Pettay, and Randell Jesup.