7.4
Advisory Published
CVE Published
Updated

CVE-2021-23961

First published: Tue Jan 26 2021(Updated: )

Further techniques that built on the slipstream research combined with a malicious webpage could have exposed both an internal network's hosts as well as services running on the user's local machine.

Credit: security@mozilla.org

Affected SoftwareAffected VersionHow to fix
<85
85
Mozilla Firefox<85.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Mozilla Thunderbird<78.10
78.10
<78.10
78.10
<78.10
78.10
debian/firefox
118.0.2-1
debian/firefox-esr
91.12.0esr-1~deb10u1
115.3.1esr-1~deb10u1
102.15.0esr-1~deb11u1
115.3.1esr-1~deb11u1
102.15.1esr-1~deb12u1
115.3.0esr-1~deb12u1
115.3.0esr-1
debian/thunderbird
1:91.12.0-1~deb10u1
1:115.3.1-1~deb10u1
1:102.13.1-1~deb11u1
1:115.3.1-1~deb11u1
1:102.15.1-1~deb12u1
1:115.3.1-1~deb12u1
1:115.3.1-1

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Parent vulnerabilities

(Appears in the following advisories)

Frequently Asked Questions

  • What is CVE-2021-23961?

    CVE-2021-23961 refers to a vulnerability that could expose both an internal network's hosts and services running on the user's local machine.

  • Which software are affected by CVE-2021-23961?

    Mozilla Thunderbird (up to version 78.10), Mozilla Firefox (up to version 85), and Mozilla Firefox ESR (up to version 78.10) are affected by CVE-2021-23961.

  • What is the severity level of CVE-2021-23961?

    CVE-2021-23961 has a severity level of medium.

  • How can I fix CVE-2021-23961?

    Ensure that you have updated Mozilla Thunderbird, Mozilla Firefox, and Mozilla Firefox ESR to the latest versions available, as specified in the remedy section.

  • Where can I find more information about CVE-2021-23961?

    You can refer to the following references for more information about CVE-2021-23961: [Bugzilla](https://bugzilla.mozilla.org/show_bug.cgi?id=1677940), [Mozilla Security Advisories](https://www.mozilla.org/en-US/security/advisories/mfsa2021-14/), and [Mozilla Security Advisories](https://www.mozilla.org/en-US/security/advisories/mfsa2021-03/).

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