6.5

CVE-2025-3909

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.

Verknüpft mit AI von unstrukturierten Daten zu bestehenden CPE der NVD
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Data is provided by the National Vulnerability Database (NVD)
Mozilla ≫ Thunderbird Version < 128.10.1
Mozilla ≫ Thunderbird Version >= 129.0 < 138.0.1
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.1% 0.276
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
134c704f-9b21-4f2e-91b3-4a467353bcc0 6.5 3.9 2.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CWE-290 Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.