REDHAT-BUG-2359793: High severity thunderbird vulnerability

Published Apr 15, 2025
·
Updated

Thunderbird processes the X-Mozilla-External-Attachment-URL header to handle attachments which can be hosted externally. When an email is opened, Thunderbird accesses the specified URL to determine file size, and navigates to it when the user clicks the attachment. Because the URL is not validated or sanitized, it can reference internal resources like chrome:// or SMB share file:// links, potentially leading to hashed Windows credential leakage and opening the door to more serious security issues. This vulnerability affects Thunderbird < 137.0.2 and Thunderbird < 128.9.2.

Affected Software

2 affected components
Mozilla Thunderbird<137.0.2
Mozilla Thunderbird<128.9.2

Event History

Apr 15, 2025
Data Sourced
via Red Hat·04:01 PM
DescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2359793?

The severity of REDHAT-BUG-2359793 is categorized as high due to the potential for remote exploitation.

2

How do I fix REDHAT-BUG-2359793?

To fix REDHAT-BUG-2359793, update Thunderbird to the latest version beyond 137.0.2 or 128.9.2.

3

What systems are affected by REDHAT-BUG-2359793?

REDHAT-BUG-2359793 affects Mozilla Thunderbird versions up to 137.0.2 and 128.9.2.

4

Is there a workaround for REDHAT-BUG-2359793?

Currently, the recommended workaround for REDHAT-BUG-2359793 is to disable the handling of external attachments.

5

What type of vulnerability is REDHAT-BUG-2359793?

REDHAT-BUG-2359793 is a remote code execution vulnerability related to external attachment handling in Thunderbird.

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