Mozilla Thunderbird up to 128.10.0/138.0.0 Header From ui layer

Summaryinfo

A vulnerability was found in Mozilla Thunderbird up to 128.10.0/138.0.0. It has been rated as problematic. The impacted element is an unknown function of the component Header Handler. Performing a manipulation of the argument From results in ui layer. This vulnerability is identified as CVE-2025-3875. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Mozilla Thunderbird up to 128.10.0/138.0.0. It has been classified as problematic. This affects an unknown function of the component Header Handler. The manipulation of the argument From with an unknown input leads to a ui layer vulnerability. CWE is classifying the issue as CWE-1021. The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with. This is going to have an impact on integrity. The summary by CVE is:

Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats [email protected] as the actual address. This vulnerability affects Thunderbird < 128.10.1 and Thunderbird < 138.0.1.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2025-3875 since 04/22/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 236871 (Debian dsa-5921 : thunderbird - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 128.10.1 or 138.0.1 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (236871), EUVD (EUVD-2025-14938) and CERT Bund (WID-SEC-2025-1850). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Mail Client Software

Vendor

• Mozilla

Name

• Thunderbird

Version

• 128.0
• 128.1
• 128.2
• 128.3
• 128.4
• 128.5
• 128.6
• 128.7
• 128.8
• 128.9
• 128.10.0
• 138.0

License

• open-source

Website

• Vendor: https://www.mozilla.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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