CVE-2021-43542: Medium severity thunderbird vulnerability

Published Dec 7, 2021
·
Updated

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.

Affected Software

12 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-1115.4.0esr-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 Thunderbird<91.4
91.4
Mozilla Firefox<95
95
Mozilla Firefox ESR<91.4
91.4
Mozilla Firefox<95.0
Mozilla Firefox ESR<91.4.0
Mozilla Thunderbird<91.4.0
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Debian Debian Linux=11.0

Event History

Dec 7, 2021
CVE Published
12:00 AM
Dec 8, 2021
CVE Published
via MITRE·09:19 PM
Data Sourced
via MITRE·09:19 PM
DescriptionWeakness
Data Sourced
via NVD·10:15 PM
DescriptionSeverityWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the vulnerability ID of this vulnerability?

The vulnerability ID is CVE-2021-43542.

2

Which software versions are affected by this vulnerability?

This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

3

How can an attacker exploit this vulnerability?

An attacker can exploit this vulnerability by using XMLHttpRequest to probe error messages for loading external protocols, allowing them to identify installed applications.

4

What is the severity level of this vulnerability?

This vulnerability has a severity level of medium.

5

Where can I find more information about this vulnerability?

You can find more information about this vulnerability at the following references: [link1](https://bugzilla.mozilla.org/show_bug.cgi?id=1723281), [link2](https://www.mozilla.org/en-US/security/advisories/mfsa2021-54/), [link3](https://www.mozilla.org/en-US/security/advisories/mfsa2021-52/).

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