Authentication Bypass Affecting thunderbird package, versions *


Severity

Recommended
high

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.05% (17th percentile)

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  • Snyk IDSNYK-RHEL8-THUNDERBIRD-10179715
  • published16 May 2025
  • disclosed14 May 2025

Introduced: 14 May 2025

NewCVE-2025-3909  (opens in a new tab)
CWE-290  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 thunderbird.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context. By crafting a nested email attachment (message/rfc822) and setting its content type to application/pdf, Thunderbird may incorrectly render it as HTML when opened, allowing the embedded JavaScript to run without requiring a file download. This behavior relies on Thunderbird auto-saving the attachment to /tmp and linking to it via the file:/// protocol, potentially enabling JavaScript execution as part of the HTML. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.

CVSS Base Scores

version 3.1