Mozilla Thunderbird up to 143 on Windows Copy as cURL escape output

Summaryinfo

A vulnerability labeled as problematic has been found in Mozilla Thunderbird up to 143 on Windows. This affects an unknown function of the component Copy as cURL Handler. Such manipulation leads to Remote Code Execution. This vulnerability is documented as CVE-2025-11713. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Mozilla Thunderbird up to 143 on Windows and classified as problematic. Affected by this issue is an unknown part of the component Copy as cURL Handler. The manipulation with an unknown input leads to a remote code execution vulnerability. Using CWE to declare the problem leads to CWE-116. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Insufficient escaping in the “Copy as cURL” feature could have been used to trick a user into executing unexpected code on Windows. This did not affect the application when running on other operating systems. This vulnerability affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.

The advisory is available at bugzilla.mozilla.org. This vulnerability is handled as CVE-2025-11713 since 10/13/2025. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 11/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 271429 (openSUSE 15 Security Update : MozillaFirefox (SUSE-SU-2025:3775-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 144 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (271429), EUVD (EUVD-2025-34201) and CERT Bund (WID-SEC-2025-2275). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• IGEL OS
• Mozilla Firefox
• Mozilla Firefox ESR
• Mozilla Thunderbird

Productinfo

Type

• Mail Client Software

Vendor

• Mozilla

Name

• Thunderbird

Version

• 143

License

• open-source

Website

• Vendor: https://www.mozilla.org/

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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