Authentication Bypass Affecting thunderbird package, versions <0:128.10.1-1.amzn2.0.1


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.05% (17th percentile)

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  • Snyk IDSNYK-AMZN2-THUNDERBIRD-10265740
  • published30 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?

Upgrade Amazon-Linux:2 thunderbird to version 0:128.10.1-1.amzn2.0.1 or higher.
This issue was patched in ALAS2-2025-2859.

NVD Description

Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 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