CVE-2020-12423: High severity thunderbird vulnerability

Published Jun 30, 2020
·
Updated

When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected. This vulnerability affects Firefox < 78.

Other sources

When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Firefox may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected.

Mozilla

When the Windows DLL "webauthn.dll" was missing from the Operating System, and a malicious one was placed in a folder in the user's %PATH%, Thunderbird may have loaded the DLL, leading to arbitrary code execution. Note: This issue only affects the Windows operating system; other operating systems are unaffected.

Mozilla

Affected Software

4 affected componentsFixes available
Mozilla Thunderbird<78
78
Mozilla Firefox<78
78
Mozilla Firefox<78.0
Microsoft Windows

Event History

Jun 30, 2020
CVE Published
12:00 AM
Jul 9, 2020
CVE Published
via MITRE·02:39 PM
Data Sourced
via MITRE·02:39 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 CVE-2020-12423?

CVE-2020-12423 is a vulnerability where the Windows DLL webauthn.dll was missing from the operating system and a malicious one was placed in a folder in the user's %PATH%, which could lead to arbitrary code execution in Thunderbird.

2

Which operating systems are affected by CVE-2020-12423?

This vulnerability only affects the Windows operating system.

3

What is the severity of CVE-2020-12423?

CVE-2020-12423 has a severity level of medium.

4

How can I fix CVE-2020-12423?

To fix this vulnerability, update Mozilla Thunderbird to version 78 or later.

5

Where can I find more information about CVE-2020-12423?

You can find more information about CVE-2020-12423 on the Mozilla website.

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