CVE-2021-29970: Use After Free

Published Jul 13, 2021
·
Updated

A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. This bug could only be triggered when accessibility was enabled.. This vulnerability affects Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.

Other sources

A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. This bug only affected Firefox when accessibility was enabled.

A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. This bug only affected Thunderbird when accessibility was enabled.

— Mozilla

Affected Software

41 affected componentsFixes available
debian/firefox
118.0.2-1
debian/firefox-esr
91.12.0esr-1~deb10u1115.3.1esr-1~deb10u1102.15.0esr-1~deb11u1115.3.1esr-1~deb11u1102.15.1esr-1~deb12u1115.3.0esr-1~deb12u1115.3.0esr-1
debian/thunderbird
1:91.12.0-1~deb10u11:115.3.1-1~deb10u11:102.13.1-1~deb11u11:115.3.1-1~deb11u11:102.15.1-1~deb12u11:115.3.1-1~deb12u11:115.3.1-1
Mozilla Firefox ESR<78.12
78.12
Mozilla Thunderbird<78.12
78.12
Mozilla Firefox<90.0
Mozilla Firefox ESR<78.12
Mozilla Thunderbird<78.12
Mozilla Firefox<90
90
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox<90.0-r0
90.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/firefox-esr<78.12.0-r0
78.12.0-r0
alpine/librewolf<90.0-r0
90.0-r0
alpine/librewolf<90.0-r0
90.0-r0
alpine/librewolf<90.0-r0
90.0-r0
alpine/librewolf<90.0-r0
90.0-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0
alpine/thunderbird<91.3.2-r0
91.3.2-r0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/firefox to a version that resolves this vulnerability.

    Fixed in 118.0.2-1
  2. Upgrade

    Upgrade debian/firefox-esr to 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
  3. Upgrade

    Upgrade debian/thunderbird to 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
  4. Upgrade

    Upgrade Firefox ESR to a version that resolves this vulnerability.

    Fixed in 78.12
  5. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 78.12
  6. Upgrade

    Upgrade Firefox to a version that resolves this vulnerability.

    Fixed in 90
  7. Upgrade

    Upgrade alpine/firefox to a version that resolves this vulnerability.

    Fixed in 90.0-r0
  8. Upgrade

    Upgrade alpine/firefox-esr to a version that resolves this vulnerability.

    Fixed in 78.12.0-r0
  9. Upgrade

    Upgrade alpine/librewolf to a version that resolves this vulnerability.

    Fixed in 90.0-r0
  10. Upgrade

    Upgrade alpine/thunderbird to a version that resolves this vulnerability.

    Fixed in 91.3.2-r0

Event History

Jul 13, 2021
CVE Published
12:00 AM
Aug 5, 2021
CVE Published
via MITRE·07:46 PM
Data Sourced
via MITRE·07:46 PM
DescriptionWeakness
Data Sourced
via NVD·08:15 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via OSV·08:15 PM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is CVE-2021-29970?

CVE-2021-29970 is a vulnerability that could allow a malicious webpage to trigger a use-after-free memory corruption and a potentially exploitable crash.

2

Which software is affected by CVE-2021-29970?

Firefox ESR 78.12, Thunderbird 78.12, and Firefox up to version 90 are affected by CVE-2021-29970.

3

What is the severity of CVE-2021-29970?

CVE-2021-29970 has a severity rating of high.

4

How can I fix CVE-2021-29970?

To fix CVE-2021-29970, update your Firefox ESR to version 78.12, Thunderbird to version 78.12, or Firefox to a version beyond 90.

5

Where can I find more information about CVE-2021-29970?

You can find more information about CVE-2021-29970 in the following references: [Bugzilla](https://bugzilla.mozilla.org/show_bug.cgi?id=1709976), [Mozilla Security Advisory](https://www.mozilla.org/en-US/security/advisories/mfsa2021-30/), [Mozilla Security Advisory](https://www.mozilla.org/en-US/security/advisories/mfsa2021-28/).

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