CVE-2025-3523: User Interface (UI) Misrepresentation of attachment URL

Published Apr 15, 2025
·
Updated

When an email contains multiple attachments with external links via the X-Mozilla-External-Attachment-URL header, only the last link is shown when hovering over any attachment. Although the correct link is used on click, the misleading hover text could trick users into downloading content from untrusted sources.

Affected Software

8 affected componentsFixes available
Mozilla Thunderbird<137.0.2
Mozilla Thunderbird<128.9.2
Mozilla Thunderbird<137.0.2
137.0.2
Mozilla Thunderbird<128.9.2
Mozilla Thunderbird>=129.0<137.0.2
ubuntu/thunderbird<1:128.12.0+build1-0ubuntu0.22.04.1
1:128.12.0+build1-0ubuntu0.22.04.1
Mozilla Thunderbird<128.9.2
128.9.2
debian/thunderbird
1:140.12.0esr-1~deb12u11:153.6.0esr-1~deb12u21:140.12.0esr-1~deb13u11:153.6.0esr-1~deb13u11:153.5.0esr-11:153.6.0esr-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 137.0.2
  2. Upgrade

    Upgrade ubuntu/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:128.12.0+build1-0ubuntu0.22.04.1
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 128.9.2
  4. Upgrade

    Upgrade debian/thunderbird to a version that resolves this vulnerability.

    Fixed in 1:140.12.0esr-1~deb12u1Fixed in 1:153.6.0esr-1~deb12u2Fixed in 1:140.12.0esr-1~deb13u1Fixed in 1:153.6.0esr-1~deb13u1Fixed in 1:153.5.0esr-1Fixed in 1:153.6.0esr-1
  5. Upgrade

    Upgrade Thunderbird to a version that resolves this vulnerability.

    Fixed in 128.9.2

Event History

Apr 15, 2025
CVE Published
via Mozilla·12:00 AM
Data Sourced
via Mozilla·12:00 AM
DescriptionSeverityAffected Software
Data Sourced
via Ubuntu·12:00 AM
RemedyDescriptionSeverityAffected Software
CVE Published
via MITRE·03:06 PM
Data Sourced
via MITRE·03:06 PM
Description
Data Sourced
via OSV·03:16 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·03:16 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via Red Hat·04:01 PM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2025-3523?

CVE-2025-3523 is classified as a moderate severity vulnerability due to the potential for user deception.

2

How does CVE-2025-3523 affect users?

CVE-2025-3523 misleads users by displaying only the last attachment link in the hover text, which could lead to the unintentional downloading of malicious content.

3

Can CVE-2025-3523 be exploited easily?

Exploitation of CVE-2025-3523 requires user interaction as it relies on clicking the attachment links.

4

What versions of Thunderbird are affected by CVE-2025-3523?

CVE-2025-3523 affects Mozilla Thunderbird versions prior to 137.0.2 and 128.9.2.

5

How do I fix CVE-2025-3523?

To mitigate CVE-2025-3523, update to the latest version of Mozilla Thunderbird that addresses this vulnerability.

Company

Resources

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