CVE Vulnerabilities

CVE-2025-3909

Authentication Bypass by Spoofing

Published: May 14, 2025 | Modified: Nov 03, 2025
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
6.5 IMPORTANT
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Ubuntu
MEDIUM
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Thunderbirds 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.

Weakness

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

Affected Software

NameVendorStart VersionEnd Version
ThunderbirdMozilla*128.10.1 (excluding)
ThunderbirdMozilla129.0 (including)138.0.1 (excluding)
Red Hat Enterprise Linux 10RedHatthunderbird-0:128.10.1-1.el10_0*
Red Hat Enterprise Linux 8RedHatthunderbird-0:128.11.0-1.el8_10*
Red Hat Enterprise Linux 8.2 Advanced Update SupportRedHatthunderbird-0:128.10.1-1.el8_2*
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRedHatthunderbird-0:128.10.1-1.el8_4*
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRedHatthunderbird-0:128.10.1-1.el8_6*
Red Hat Enterprise Linux 8.6 Telecommunications Update ServiceRedHatthunderbird-0:128.10.1-1.el8_6*
Red Hat Enterprise Linux 8.6 Update Services for SAP SolutionsRedHatthunderbird-0:128.10.1-1.el8_6*
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRedHatthunderbird-0:128.10.1-1.el8_8*
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRedHatthunderbird-0:128.10.1-1.el8_8*
Red Hat Enterprise Linux 9RedHatthunderbird-0:128.10.1-1.el9_6*
Red Hat Enterprise Linux 9.0 Update Services for SAP SolutionsRedHatthunderbird-0:128.10.1-1.el9_0*
Red Hat Enterprise Linux 9.2 Extended Update SupportRedHatthunderbird-0:128.10.1-1.el9_2*
Red Hat Enterprise Linux 9.4 Extended Update SupportRedHatthunderbird-0:128.10.1-1.el9_4*
ThunderbirdUbuntufocal*
ThunderbirdUbuntujammy*
ThunderbirdUbuntuoracular*
ThunderbirdUbuntuupstream*

References