Mozilla Firefox up to 136 URL ui layer

Summaryinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 136. This impacts an unknown function of the component URL Handler. Such manipulation leads to ui layer. This vulnerability is documented as CVE-2025-3029. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 136. It has been rated as problematic. Affected by this issue is some unknown functionality of the component URL Handler. The manipulation with an unknown input leads to a ui layer vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. CVE summarizes:

A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability was fixed in Firefox 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.

The advisory is shared for download at bugzilla.mozilla.org. This vulnerability is handled as CVE-2025-3029 since 03/31/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 04/15/2026).

The vulnerability scanner Nessus provides a plugin with the ID 233651 (Mozilla Firefox ESR < 128.9), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 137 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (233651). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 136

License

• open-source

Website

• Vendor: https://www.mozilla.org/
• Product: https://www.mozilla.org/en-US/firefox/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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