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CVE-2025-3522

Leak of hashed Window credentials via crafted attachment URL

Published: Apr 15, 2025Updated: Apr 13, 2026 Sources: CVE List NVD BDUCWE-601
6.3MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 86.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:LI:LA:L
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:LAvailability
Low
Open in CVSS calculator →

Weaknesses

CWE-601

Affected Products

Mozilla Corp.
oss-project·USaka Mozilla
ThunderbirdOn-premDesktop App
Communications / email-server-client
Thunderbird ESR
Consumer Software
ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro
ООО «РусБИТех-Астра»
commercial·RUaka rusbitech-astra
Astra Linux Special EditionOn-premOS
Operating Systems / linux-distro
АО «ИВК»
commercial·RUaka ivk
АЛЬТ СП 10On-premOS
Operating Systems / linux-distro
and 2 more affected products View all →

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://bugzilla.mozilla.org/show_bug.cgi?id=1955372
bugzilla.mozilla.org
https://www.mozilla.org/security/advisories/mfsa2025-26/
mozilla.org
https://www.mozilla.org/security/advisories/mfsa2025-27/
mozilla.org
and 4 more references View all →

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