CVE-2025-3522

Publication date 15 April 2025

Last updated 22 July 2025


Ubuntu priority

Cvss 3 Severity Score

6.3 · Medium

Score breakdown

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.

Status

Package Ubuntu Release Status
thunderbird 25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Fixed 1:128.12.0+build1-0ubuntu0.22.04.1
20.04 LTS focal Not in release

Severity score breakdown

Parameter Value
Base score 6.3 · Medium
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Scope Unchanged
Confidentiality Low
Integrity impact Low
Availability impact Low
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L