Vulnerability · Published Apr 15, 2025 · Assigned by mozilla
CVE-2025-3522Leak of hashed Window credentials via crafted attachment URL
Medium 6.3
In plain English
A medium-severity open redirect in Thunderbird from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 was fixed in Thunderbird 137.0.2 and Thunderbird 128.9.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | thunderbird | 128.10.0-1.el10_0.alma.1 | ALSA-2025:7507 |
| AlmaLinux:8 | thunderbird | 128.9.2-1.el8_10.alma.1 | ALSA-2025:4649 |
| AlmaLinux:9 | thunderbird | 128.9.2-1.el9_5.alma.1 | ALSA-2025:4229 |
| AlmaLinux:9 | thunderbird | 128.10.0-1.el9_6.alma.1 | ALSA-2025:7435 |
| Debian:12 | thunderbird | 1:128.10.0esr-1~deb12u1 | DSA-5912-1 |
| Debian:12 | thunderbird | 1:128.10.0esr-1~deb12u1 | DEBIAN-CVE-2025-3522 |
| Debian:13 | thunderbird | 1:128.10.0esr-1 | DEBIAN-CVE-2025-3522 |
| Debian:14 | thunderbird | 1:128.10.0esr-1 | DEBIAN-CVE-2025-3522 |
| Rocky Linux:9 | thunderbird | 0:128.10.0-1.el9_5 | RLSA-2025:7435 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2025-3522 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | USN-7663-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Thunderbird | see references |
Weakness: CWE-601 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L