CVE-2021-23998: Medium severity thunderbird vulnerability

Published Apr 19, 2021
·
Updated

Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon from an HTTPS page.

Affected Software

9 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 Thunderbird<78.10
78.10
Mozilla Firefox<88.0
Mozilla Firefox ESR<78.10
Mozilla Thunderbird<78.10
Mozilla Firefox<88
88
Mozilla Firefox ESR<78.10
78.10

Event History

Apr 19, 2021
CVE Published
via Mozilla·12:00 AM
Jun 24, 2021
CVE Published
via MITRE·01:25 PM
Data Sourced
via MITRE·01:25 PM
DescriptionWeakness

Parent advisories

This vulnerability appears in the following advisories.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2021-23998?

CVE-2021-23998 has a moderate severity rating as it can mislead users by displaying a secure lock icon on an insecure HTTP page.

2

How do I fix CVE-2021-23998?

To fix CVE-2021-23998, upgrade to Mozilla Thunderbird or Firefox ESR version 78.10 or later.

3

Which versions are affected by CVE-2021-23998?

CVE-2021-23998 affects Mozilla Thunderbird versions prior to 78.10 and Mozilla Firefox ESR versions prior to 78.10.

4

What is the impact of CVE-2021-23998 on users?

The impact of CVE-2021-23998 is that it can create a false sense of security for users by displaying a secure lock symbol on an unsecured HTTP page.

5

Is CVE-2021-23998 exploitable remotely?

CVE-2021-23998 is potentially exploitable remotely as it arises from the way new windows handle navigation between secure and insecure content.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203